/****************************************************************************
 **
 ** This file is part of the Zip Utils:
 **
 ** Qmmander uses the Zip Utils for file compression.
 **
 ** The Zip Utils were created by Lucian Wischik (ljw1004)
 ** and published on CodeProject.
 **
 ** Article:  Zip Utils - clean, elegant, simple, C++/Win32
 ** Date:     06/24/2004
 ** URL:      http://www.codeproject.com/KB/files/zip_utils.aspx
 **
 ** License      : Public Domain
 ** License Infos: http://creativecommons.org/licenses/publicdomain/
 **
 ****************************************************************************/
#define _UNICODE
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include "zip.h"

// THIS FILE is almost entirely based upon code by info-zip.
// It has been modified by Lucian Wischik. The modifications
// were a complete rewrite of the bit of code that generates the
// layout of the zipfile, and support for zipping to/from memory
// or handles or pipes or pagefile or diskfiles, encryption, unicode.
// The original code may be found at http://www.info-zip.org
// The original copyright text follows.
//
//
//
// This is version 1999-Oct-05 of the Info-ZIP copyright and license.
// The definitive version of this document should be available at
// ftp://ftp.cdrom.com/pub/infozip/license.html indefinitely.
//
// Copyright (c) 1990-1999 Info-ZIP.  All rights reserved.
//
// For the purposes of this copyright and license, "Info-ZIP" is defined as
// the following set of individuals:
//
//   Mark Adler, John Bush, Karl Davis, Harald Denker, Jean-Michel Dubois,
//   Jean-loup Gailly, Hunter Goatley, Ian Gorman, Chris Herborth, Dirk Haase,
//   Greg Hartwig, Robert Heath, Jonathan Hudson, Paul Kienitz, David Kirschbaum,
//   Johnny Lee, Onno van der Linden, Igor Mandrichenko, Steve P. Miller,
//   Sergio Monesi, Keith Owens, George Petrov, Greg Roelofs, Kai Uwe Rommel,
//   Steve Salisbury, Dave Smith, Christian Spieler, Antoine Verheijen,
//   Paul von Behren, Rich Wales, Mike White
//
// This software is provided "as is," without warranty of any kind, express
// or implied.  In no event shall Info-ZIP or its contributors be held liable
// for any direct, indirect, incidental, special or consequential damages
// arising out of the use of or inability to use this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
//    1. Redistributions of source code must retain the above copyright notice,
//       definition, disclaimer, and this list of conditions.
//
//    2. Redistributions in binary form must reproduce the above copyright
//       notice, definition, disclaimer, and this list of conditions in
//       documentation and/or other materials provided with the distribution.
//
//    3. Altered versions--including, but not limited to, ports to new operating
//       systems, existing ports with new graphical interfaces, and dynamic,
//       shared, or static library versions--must be plainly marked as such
//       and must not be misrepresented as being the original source.  Such
//       altered versions also must not be misrepresented as being Info-ZIP
//       releases--including, but not limited to, labeling of the altered
//       versions with the names "Info-ZIP" (or any variation thereof, including,
//       but not limited to, different capitalizations), "Pocket UnZip," "WiZ"
//       or "MacZip" without the explicit permission of Info-ZIP.  Such altered
//       versions are further prohibited from misrepresentative use of the
//       Zip-Bugs or Info-ZIP e-mail addresses or of the Info-ZIP URL(s).
//
//    4. Info-ZIP retains the right to use the names "Info-ZIP," "Zip," "UnZip,"
//       "WiZ," "Pocket UnZip," "Pocket Zip," and "MacZip" for its own source and
//       binary releases.
//
typedef unsigned char uch; // unsigned 8-bit value
typedef unsigned short ush; // unsigned 16-bit value
typedef unsigned long ulg; // unsigned 32-bit value
typedef size_t extent; // file size
typedef unsigned Pos; // must be at least 32 bits
typedef unsigned IPos; // A Pos is an index in the character window. Pos is used only for parameter passing
#ifndef EOF
#define EOF (-1)
#endif 
// Error return values.  The values 0..4 and 12..18 follow the conventions
// of PKZIP.   The values 4..10 are all assigned to "insufficient memory"
// by PKZIP, so the codes 5..10 are used here for other purposes.
#define ZE_MISS         -1      // used by procname(), zipbare()
#define ZE_OK           0       // success
#define ZE_EOF          2       // unexpected end of zip file
#define ZE_FORM         3       // zip file structure error
#define ZE_MEM          4       // out of memory
#define ZE_LOGIC        5       // internal logic error
#define ZE_BIG          6       // entry too large to split
#define ZE_NOTE         7       // invalid comment format
#define ZE_TEST         8       // zip test (-T) failed or out of memory
#define ZE_ABORT        9       // user interrupt or termination
#define ZE_TEMP         10      // error using a temp file
#define ZE_READ         11      // read or seek error
#define ZE_NONE         12      // nothing to do
#define ZE_NAME         13      // missing or empty zip file
#define ZE_WRITE        14      // error writing to a file
#define ZE_CREAT        15      // couldn't open to write
#define ZE_PARMS        16      // bad command line
#define ZE_OPEN         18      // could not open a specified file to read
#define ZE_MAXERR       18      // the highest error number
// internal file attribute
#define UNKNOWN (-1)
#define BINARY  0
#define ASCII   1
#define BEST -1                 // Use best method (deflation or store)
#define STORE 0                 // Store method
#define DEFLATE 8               // Deflation method
#define CRCVAL_INITIAL  0L
// MSDOS file or directory attributes
#define MSDOS_HIDDEN_ATTR 0x02
#define MSDOS_DIR_ATTR 0x10
// Lengths of headers after signatures in bytes
#define LOCHEAD 26
#define CENHEAD 42
#define ENDHEAD 18
// Definitions for extra field handling:
#define EB_HEADSIZE       4     /* length of a extra field block header */
#define EB_LEN            2     /* offset of data length field in header */
#define EB_UT_MINLEN      1     /* minimal UT field contains Flags byte */
#define EB_UT_FLAGS       0     /* byte offset of Flags field */
#define EB_UT_TIME1       1     /* byte offset of 1st time value */
#define EB_UT_FL_MTIME    (1 << 0)      /* mtime present */
#define EB_UT_FL_ATIME    (1 << 1)      /* atime present */
#define EB_UT_FL_CTIME    (1 << 2)      /* ctime present */
#define EB_UT_LEN(n)      (EB_UT_MINLEN + 4 * (n))
#define EB_L_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(3))
#define EB_C_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(1))
// Macros for writing machine integers to little-endian format
#define PUTSH(a,f) {char _putsh_c=(char)((a)&0xff); wfunc(param,&_putsh_c,1); _putsh_c=(char)((a)>>8); wfunc(param,&_putsh_c,1);}
#define PUTLG(a,f) {PUTSH((a) & 0xffff,(f)) PUTSH((a) >> 16,(f))}
// -- Structure of a ZIP file --
// Signatures for zip file information headers
#define LOCSIG     0x04034b50L
#define CENSIG     0x02014b50L
#define ENDSIG     0x06054b50L
#define EXTLOCSIG  0x08074b50L
#define MIN_MATCH  3
#define MAX_MATCH  258
// The minimum and maximum match lengths
#define WSIZE  (0x8000)
// Maximum window size = 32K. If you are really short of memory, compile
// with a smaller WSIZE but this reduces the compression ratio for files
// of size > WSIZE. WSIZE must be a power of two in the current implementation.
//
#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
// Minimum amount of lookahead, except at the end of the input file.
// See deflate.c for comments about the MIN_MATCH+1.
//
#define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
// In order to simplify the code, particularly on 16 bit machines, match
// distances are limited to MAX_DIST instead of WSIZE.
//
#define ZIP_HANDLE   1
#define ZIP_FILENAME 2
#define ZIP_MEMORY   3
#define ZIP_FOLDER   4
// ===========================================================================
// Constants
//
#define MAX_BITS 15
// All codes must not exceed MAX_BITS bits
#define MAX_BL_BITS 7
// Bit length codes must not exceed MAX_BL_BITS bits
#define LENGTH_CODES 29
// number of length codes, not counting the special END_BLOCK code
#define LITERALS  256
// number of literal bytes 0..255
#define END_BLOCK 256
// end of block literal code
#define L_CODES (LITERALS+1+LENGTH_CODES)
// number of Literal or Length codes, including the END_BLOCK code
#define D_CODES   30
// number of distance codes
#define BL_CODES  19
// number of codes used to transfer the bit lengths
#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES    2
// The three kinds of block type
#define LIT_BUFSIZE  0x8000
#define DIST_BUFSIZE  LIT_BUFSIZE
// Sizes of match buffers for literals/lengths and distances.  There are
// 4 reasons for limiting LIT_BUFSIZE to 64K:
//   - frequencies can be kept in 16 bit counters
//   - if compression is not successful for the first block, all input data is
//     still in the window so we can still emit a stored block even when input
//     comes from standard input.  (This can also be done for all blocks if
//     LIT_BUFSIZE is not greater than 32K.)
//   - if compression is not successful for a file smaller than 64K, we can
//     even emit a stored file instead of a stored block (saving 5 bytes).
//   - creating new Huffman trees less frequently may not provide fast
//     adaptation to changes in the input data statistics. (Take for
//     example a binary file with poorly compressible code followed by
//     a highly compressible string table.) Smaller buffer sizes give
//     fast adaptation but have of course the overhead of transmitting trees
//     more frequently.
//   - I can't count above 4
// The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
// memory at the expense of compression). Some optimizations would be possible
// if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
//
#define REP_3_6      16
// repeat previous bit length 3-6 times (2 bits of repeat count)
#define REPZ_3_10    17
// repeat a zero length 3-10 times  (3 bits of repeat count)
#define REPZ_11_138  18
// repeat a zero length 11-138 times  (7 bits of repeat count)
#define HEAP_SIZE (2*L_CODES+1)
// maximum heap size
// ===========================================================================
// Local data used by the "bit string" routines.
//
#define Buf_size (8 * 2*sizeof(char))
// Number of bits used within bi_buf. (bi_buf may be implemented on
// more than 16 bits on some systems.)
// Output a 16 bit value to the bit stream, lower (oldest) byte first
#define PUTSHORT(state,w) \
{ if (state.bs.out_offset >= state.bs.out_size-1) \
state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
state.bs.out_buf[state.bs.out_offset++] = (char) ((w) & 0xff); \
state.bs.out_buf[state.bs.out_offset++] = (char) ((ush)(w) >> 8); \
}
#define PUTBYTE(state,b) \
{ if (state.bs.out_offset >= state.bs.out_size) \
state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
state.bs.out_buf[state.bs.out_offset++] = (char) (b); \
}
// DEFLATE.CPP HEADER
#define HASH_BITS  15
// For portability to 16 bit machines, do not use values above 15.
#define HASH_SIZE (unsigned)(1<<HASH_BITS)
#define HASH_MASK (HASH_SIZE-1)
#define WMASK     (WSIZE-1)
// HASH_SIZE and WSIZE must be powers of two
#define NIL 0
// Tail of hash chains
#define FAST 4
#define SLOW 2
// speed options for the general purpose bit flag
#define TOO_FAR 4096
// Matches of length 3 are discarded if their distance exceeds TOO_FAR
#define EQUAL 0
// result of memcmp for equal strings
// ===========================================================================
// Local data used by the "longest match" routines.
#define H_SHIFT  ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
// Number of bits by which ins_h and del_h must be shifted at each
// input step. It must be such that after MIN_MATCH steps, the oldest
// byte no longer takes part in the hash key, that is:
//   H_SHIFT * MIN_MATCH >= HASH_BITS
#define max_insert_length  max_lazy_match
// Insert new strings in the hash table only if the match length
// is not greater than this length. This saves time but degrades compression.
// max_insert_length is used only for compression levels <= 3.
const int extra_lbits[LENGTH_CODES] // extra bits for each length code
 = 
{
    0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
};
const int extra_dbits[D_CODES] // extra bits for each distance code
 = 
{
    0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13
};
const int extra_blbits[BL_CODES] // extra bits for each bit length code
 = 
{
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7
};
const uch bl_order[BL_CODES] = 
{
    16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
// The lengths of the bit length codes are sent in order of decreasing
// probability, to avoid transmitting the lengths for unused bit length codes.
typedef struct config
{
    ush good_length; // reduce lazy search above this match length
    ush max_lazy; // do not perform lazy search above this match length
    ush nice_length; // quit search above this match length
    ush max_chain;
} config;
// Values for max_lazy_match, good_match, nice_match and max_chain_length,
// depending on the desired pack level (0..9). The values given below have
// been tuned to exclude worst case performance for pathological files.
// Better values may be found for specific files.
//
const config configuration_table[10] = 
{
    //  good lazy nice chain
    {
        0, 0, 0, 0
    }
    ,  // 0 store only
    {
        4, 4, 8, 4
    }
    ,  // 1 maximum speed, no lazy matches
    {
        4, 5, 16, 8
    }
    ,  // 2
    {
        4, 6, 32, 32
    }
    ,  // 3
    {
        4, 4, 16, 16
    }
    ,  // 4 lazy matches */
    {
        8, 16, 32, 32
    }
    ,  // 5
    {
        8, 16, 128, 128
    }
    ,  // 6
    {
        8, 32, 128, 256
    }
    ,  // 7
    {
        32, 128, 258, 1024
    }
    ,  // 8
    {
        32, 258, 258, 4096
    }
}; // 9 maximum compression */
// Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
// For deflate_fast() (levels <= 3) good is ignored and lazy has a different meaning.
// Data structure describing a single value and its code string.
typedef struct ct_data
{
    union
    {
        ush freq; // frequency count
        ush code; // bit string
    } fc;
    union
    {
        ush dad; // father node in Huffman tree
        ush len; // length of bit string
    } dl;
}

ct_data;
typedef struct tree_desc
{
    ct_data *dyn_tree; // the dynamic tree
    ct_data *static_tree; // corresponding static tree or NULL
    const int *extra_bits; // extra bits for each code or NULL
    int extra_base; // base index for extra_bits
    int elems; // max number of elements in the tree
    int max_length; // max bit length for the codes
    int max_code; // largest code with non zero frequency
} tree_desc;
class TTreeState
{
public:
    TTreeState();
    ct_data dyn_ltree[HEAP_SIZE]; // literal and length tree
    ct_data dyn_dtree[2 *D_CODES + 1]; // distance tree
    ct_data static_ltree[L_CODES + 2]; // the static literal tree...
    // ... Since the bit lengths are imposed, there is no need for the L_CODES
    // extra codes used during heap construction. However the codes 286 and 287
    // are needed to build a canonical tree (see ct_init below).
    ct_data static_dtree[D_CODES]; // the static distance tree...
    // ... (Actually a trivial tree since all codes use 5 bits.)
    ct_data bl_tree[2 *BL_CODES + 1]; // Huffman tree for the bit lengths
    tree_desc l_desc;
    tree_desc d_desc;
    tree_desc bl_desc;
    ush bl_count[MAX_BITS + 1]; // number of codes at each bit length for an optimal tree
    int heap[2 *L_CODES + 1]; // heap used to build the Huffman trees
    int heap_len; // number of elements in the heap
    int heap_max; // element of largest frequency
    // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
    // The same heap array is used to build all trees.
    uch depth[2 *L_CODES + 1];
    // Depth of each subtree used as tie breaker for trees of equal frequency
    uch length_code[MAX_MATCH - MIN_MATCH + 1];
    // length code for each normalized match length (0 == MIN_MATCH)
    uch dist_code[512];
    // distance codes. The first 256 values correspond to the distances
    // 3 .. 258, the last 256 values correspond to the top 8 bits of
    // the 15 bit distances.
    int base_length[LENGTH_CODES];
    // First normalized length for each code (0 = MIN_MATCH)
    int base_dist[D_CODES];
    // First normalized distance for each code (0 = distance of 1)
    uch far l_buf[LIT_BUFSIZE]; // buffer for literals/lengths
    ush far d_buf[DIST_BUFSIZE]; // buffer for distances
    uch flag_buf[(LIT_BUFSIZE / 8)];
    // flag_buf is a bit array distinguishing literals from lengths in
    // l_buf, and thus indicating the presence or absence of a distance.
    unsigned last_lit; // running index in l_buf
    unsigned last_dist; // running index in d_buf
    unsigned last_flags; // running index in flag_buf
    uch flags; // current flags not yet saved in flag_buf
    uch flag_bit; // current bit used in flags
    // bits are filled in flags starting at bit 0 (least significant).
    // Note: these flags are overkill in the current code since we don't
    // take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
    ulg opt_len; // bit length of current block with optimal trees
    ulg static_len; // bit length of current block with static trees
    ulg cmpr_bytelen; // total byte length of compressed file
    ulg cmpr_len_bits; // number of bits past 'cmpr_bytelen'
    ulg input_len; // total byte length of input file
    // input_len is for debugging only since we can get it by other means.
    ush *file_type; // pointer to UNKNOWN, BINARY or ASCII
    //  int *file_method;     // pointer to DEFLATE or STORE
};
TTreeState::TTreeState()
{
    tree_desc a = 
    {
        dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES, MAX_BITS, 0
    };
    l_desc = a;
    tree_desc b = 
    {
        dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0
    };
    d_desc = b;
    tree_desc c = 
    {
        bl_tree, NULL, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0
    };
    bl_desc = c;
    last_lit = 0;
    last_dist = 0;
    last_flags = 0;
}

class TBitState
{
public:
    int flush_flg;
    //
    unsigned bi_buf;
    // Output buffer. bits are inserted starting at the bottom (least significant
    // bits). The width of bi_buf must be at least 16 bits.
    int bi_valid;
    // Number of valid bits in bi_buf.  All bits above the last valid bit
    // are always zero.
    char *out_buf;
    // Current output buffer.
    unsigned out_offset;
    // Current offset in output buffer.
    // On 16 bit machines, the buffer is limited to 64K.
    unsigned out_size;
    // Size of current output buffer
    ulg bits_sent; // bit length of the compressed data  only needed for debugging???
};
class TDeflateState
{
public:
    TDeflateState()
    {
        window_size = 0;
    }
    uch window[2L *WSIZE];
    // Sliding window. Input bytes are read into the second half of the window,
    // and move to the first half later to keep a dictionary of at least WSIZE
    // bytes. With this organization, matches are limited to a distance of
    // WSIZE-MAX_MATCH bytes, but this ensures that IO is always
    // performed with a length multiple of the block size. Also, it limits
    // the window size to 64K, which is quite useful on MSDOS.
    // To do: limit the window size to WSIZE+CBSZ if SMALL_MEM (the code would
    // be less efficient since the data would have to be copied WSIZE/CBSZ times)
    Pos prev[WSIZE];
    // Link to older string with same hash index. To limit the size of this
    // array to 64K, this link is maintained only for the last 32K strings.
    // An index in this array is thus a window index modulo 32K.
    Pos head[HASH_SIZE];
    // Heads of the hash chains or NIL. If your compiler thinks that
    // HASH_SIZE is a dynamic value, recompile with -DDYN_ALLOC.
    ulg window_size;
    // window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
    // input file length plus MIN_LOOKAHEAD.
    long block_start;
    // window position at the beginning of the current output block. Gets
    // negative when the window is moved backwards.
    int sliding;
    // Set to false when the input file is already in memory
    unsigned ins_h; // hash index of string to be inserted
    unsigned int prev_length;
    // Length of the best match at previous step. Matches not greater than this
    // are discarded. This is used in the lazy match evaluation.
    unsigned strstart; // start of string to insert
    unsigned match_start; // start of matching string
    int eofile; // flag set at end of input file
    unsigned lookahead; // number of valid bytes ahead in window
    unsigned max_chain_length;
    // To speed up deflation, hash chains are never searched beyond this length.
    // A higher limit improves compression ratio but degrades the speed.
    unsigned int max_lazy_match;
    // Attempt to find a better match only when the current match is strictly
    // smaller than this value. This mechanism is used only for compression
    // levels >= 4.
    unsigned good_match;
    // Use a faster search when the previous match is longer than this
    int nice_match; // Stop searching when current match exceeds this
};
typedef __int64 lutime_t; // define it ourselves since we don't include time.h
typedef struct iztimes
{
    lutime_t atime, mtime, ctime;
} iztimes; // access, modify, create times
typedef struct zlist
{
    ush vem, ver, flg, how; // See central header in zipfile.c for what vem..off are
    ulg tim, crc, siz, len;
    extent nam, ext, cext, com; // offset of ext must be >= LOCHEAD
    ush dsk, att, lflg; // offset of lflg must be >= LOCHEAD
    ulg atx, off;
    char name[MAX_PATH]; // File name in zip file
    char *extra; // Extra field (set only if ext != 0)
    char *cextra; // Extra in central (set only if cext != 0)
    char *comment; // Comment (set only if com != 0)
    char iname[MAX_PATH]; // Internal file name after cleanup
    char zname[MAX_PATH]; // External version of internal name
    int mark; // Marker for files to operate on
    int trash; // Marker for files to delete
    int dosflag; // Set to force MSDOS file attributes
    struct zlist far *nxt; // Pointer to next header in list
} TZipFileInfo;
struct TState;
typedef unsigned(*READFUNC)(TState &state, char *buf, unsigned size);
typedef unsigned(*FLUSHFUNC)(void *param, const char *buf, unsigned *size);
typedef unsigned(*WRITEFUNC)(void *param, const char *buf, unsigned size);
struct TState
{
    void *param;
    int level;
    bool seekable;
    READFUNC readfunc;
    FLUSHFUNC flush_outbuf;
    TTreeState ts;
    TBitState bs;
    TDeflateState ds;
    const char *err;
};
void Assert(TState &state, bool cond, const char *msg)
{
    if (cond)
    {
        return ;
    }
    state.err = msg;
}

void __cdecl Trace(const char *x, ...)
{
    va_list paramList;
    va_start(paramList, x);
    paramList;
    va_end(paramList);
}

void __cdecl Tracec(bool, const char *x, ...)
{
    va_list paramList;
    va_start(paramList, x);
    paramList;
    va_end(paramList);
}

// ===========================================================================
// Local (static) routines in this file.
//
void init_block(TState &);
void pqdownheap(TState &, ct_data *tree, int k);
void gen_bitlen(TState &, tree_desc *desc);
void gen_codes(TState &state, ct_data *tree, int max_code);
void build_tree(TState &, tree_desc *desc);
void scan_tree(TState &, ct_data *tree, int max_code);
void send_tree(TState &state, ct_data *tree, int max_code);
int build_bl_tree(TState &);
void send_all_trees(TState &state, int lcodes, int dcodes, int blcodes);
void compress_block(TState &state, ct_data *ltree, ct_data *dtree);
void set_file_type(TState &);
void send_bits(TState &state, int value, int length);
unsigned bi_reverse(unsigned code, int len);
void bi_windup(TState &state);
void copy_block(TState &state, char *buf, unsigned len, int header);
#define send_code(state, c, tree) send_bits(state, tree[c].fc.code, tree[c].dl.len)
// Send a code of the given tree. c and tree must not have side effects
// alternatively...
//#define send_code(state, c, tree)
//     { if (state.verbose>1) fprintf(stderr,"\ncd %3d ",(c));
//       send_bits(state, tree[c].fc.code, tree[c].dl.len); }
#define d_code(dist) ((dist) < 256 ? state.ts.dist_code[dist] : state.ts.dist_code[256+((dist)>>7)])
// Mapping from a distance to a distance code. dist is the distance - 1 and
// must not have side effects. dist_code[256] and dist_code[257] are never used.
#define Max(a,b) (a >= b ? a : b)
/* the arguments must not have side effects */
/* ===========================================================================
 * Allocate the match buffer, initialize the various tables and save the
 * location of the internal file attribute (ascii/binary) and method
 * (DEFLATE/STORE).
 */
void ct_init(TState &state, ush *attr)
{
    int n; /* iterates over tree elements */
    int bits; /* bit counter */
    int length; /* length value */
    int code; /* code value */
    int dist; /* distance index */
    state.ts.file_type = attr;
    //state.ts.file_method = method;
    state.ts.cmpr_bytelen = state.ts.cmpr_len_bits = 0L;
    state.ts.input_len = 0L;
    if (state.ts.static_dtree[0].dl.len != 0)
    {
        return ;
    }
    /* ct_init already called */
    /* Initialize the mapping length (0..255) -> length code (0..28) */
    length = 0;
    for (code = 0; code < LENGTH_CODES - 1; code++)
    {
        state.ts.base_length[code] = length;
        for (n = 0; n < (1 << extra_lbits[code]); n++)
        {
            state.ts.length_code[length++] = (uch)code;
        }
    }
    Assert(state, length == 256, "ct_init: length != 256");
    /* Note that the length 255 (match length 258) can be represented
     * in two different ways: code 284 + 5 bits or code 285, so we
     * overwrite length_code[255] to use the best encoding:
     */
    state.ts.length_code[length - 1] = (uch)code;
    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
    dist = 0;
    for (code = 0; code < 16; code++)
    {
        state.ts.base_dist[code] = dist;
        for (n = 0; n < (1 << extra_dbits[code]); n++)
        {
            state.ts.dist_code[dist++] = (uch)code;
        }
    }
    Assert(state, dist == 256, "ct_init: dist != 256");
    dist >>= 7; /* from now on, all distances are divided by 128 */
    for (; code < D_CODES; code++)
    {
        state.ts.base_dist[code] = dist << 7;
        for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++)
        {
            state.ts.dist_code[256+dist++] = (uch)code;
        }
    }
    Assert(state, dist == 256, "ct_init: 256+dist != 512");
    /* Construct the codes of the static literal tree */
    for (bits = 0; bits <= MAX_BITS; bits++)
    {
        state.ts.bl_count[bits] = 0;
    }
    n = 0;
    while (n <= 143)
    {
        state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    }
    while (n <= 255)
    {
        state.ts.static_ltree[n++].dl.len = 9, state.ts.bl_count[9]++;
    }
    while (n <= 279)
    {
        state.ts.static_ltree[n++].dl.len = 7, state.ts.bl_count[7]++;
    }
    while (n <= 287)
    {
        state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    }
    /* fc.codes 286 and 287 do not exist, but we must include them in the
     * tree construction to get a canonical Huffman tree (longest code
     * all ones)
     */
    gen_codes(state, (ct_data*)state.ts.static_ltree, L_CODES + 1);
    /* The static distance tree is trivial: */
    for (n = 0; n < D_CODES; n++)
    {
        state.ts.static_dtree[n].dl.len = 5;
        state.ts.static_dtree[n].fc.code = (ush)bi_reverse(n, 5);
    }
    /* Initialize the first block of the first file: */
    init_block(state);
}

/* ===========================================================================
 * Initialize a new block.
 */
void init_block(TState &state)
{
    int n; /* iterates over tree elements */
    /* Initialize the trees. */
    for (n = 0; n < L_CODES; n++)
    {
        state.ts.dyn_ltree[n].fc.freq = 0;
    }
    for (n = 0; n < D_CODES; n++)
    {
        state.ts.dyn_dtree[n].fc.freq = 0;
    }
    for (n = 0; n < BL_CODES; n++)
    {
        state.ts.bl_tree[n].fc.freq = 0;
    }
    state.ts.dyn_ltree[END_BLOCK].fc.freq = 1;
    state.ts.opt_len = state.ts.static_len = 0L;
    state.ts.last_lit = state.ts.last_dist = state.ts.last_flags = 0;
    state.ts.flags = 0;
    state.ts.flag_bit = 1;
}

#define SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */
/* ===========================================================================
 * Remove the smallest element from the heap and recreate the heap with
 * one less element. Updates heap and heap_len.
 */
#define pqremove(tree, top) \
{\
top = state.ts.heap[SMALLEST]; \
state.ts.heap[SMALLEST] = state.ts.heap[state.ts.heap_len--]; \
pqdownheap(state,tree, SMALLEST); \
}
/* ===========================================================================
 * Compares to subtrees, using the tree depth as tie breaker when
 * the subtrees have equal frequency. This minimizes the worst case length.
 */
#define smaller(tree, n, m) \
(tree[n].fc.freq < tree[m].fc.freq || \
(tree[n].fc.freq == tree[m].fc.freq && state.ts.depth[n] <= state.ts.depth[m]))
/* ===========================================================================
 * Restore the heap property by moving down the tree starting at node k,
 * exchanging a node with the smallest of its two sons if necessary, stopping
 * when the heap property is re-established (each father smaller than its
 * two sons).
 */
void pqdownheap(TState &state, ct_data *tree, int k)
{
    int v = state.ts.heap[k];
    int j = k << 1; /* left son of k */
    int htemp; /* required because of bug in SASC compiler */
    while (j <= state.ts.heap_len)
    {
        /* Set j to the smallest of the two sons: */
        if (j < state.ts.heap_len && smaller(tree, state.ts.heap[j + 1], state.ts.heap[j]))
        {
            j++;
        }
        /* Exit if v is smaller than both sons */
        htemp = state.ts.heap[j];
        if (smaller(tree, v, htemp))
        {
            break;
        }
        /* Exchange v with the smallest son */
        state.ts.heap[k] = htemp;
        k = j;
        /* And continue down the tree, setting j to the left son of k */
        j <<= 1;
    }
    state.ts.heap[k] = v;
}

/* ===========================================================================
 * Compute the optimal bit lengths for a tree and update the total bit length
 * for the current block.
 * IN assertion: the fields freq and dad are set, heap[heap_max] and
 *    above are the tree nodes sorted by increasing frequency.
 * OUT assertions: the field len is set to the optimal bit length, the
 *     array bl_count contains the frequencies for each bit length.
 *     The length opt_len is updated; static_len is also updated if stree is
 *     not null.
 */
void gen_bitlen(TState &state, tree_desc *desc)
{
    ct_data *tree = desc->dyn_tree;
    const int *extra = desc->extra_bits;
    int base = desc->extra_base;
    int max_code = desc->max_code;
    int max_length = desc->max_length;
    ct_data *stree = desc->static_tree;
    int h; /* heap index */
    int n, m; /* iterate over the tree elements */
    int bits; /* bit length */
    int xbits; /* extra bits */
    ush f; /* frequency */
    int overflow = 0; /* number of elements with bit length too large */
    for (bits = 0; bits <= MAX_BITS; bits++)
    {
        state.ts.bl_count[bits] = 0;
    }
    /* In a first pass, compute the optimal bit lengths (which may
     * overflow in the case of the bit length tree).
     */
    tree[state.ts.heap[state.ts.heap_max]].dl.len = 0; /* root of the heap */
    for (h = state.ts.heap_max + 1; h < HEAP_SIZE; h++)
    {
        n = state.ts.heap[h];
        bits = tree[tree[n].dl.dad].dl.len + 1;
        if (bits > max_length)
        {
            bits = max_length, overflow++;
        }
        tree[n].dl.len = (ush)bits;
        /* We overwrite tree[n].dl.dad which is no longer needed */
        if (n > max_code)
        {
            continue;
        }
        /* not a leaf node */
        state.ts.bl_count[bits]++;
        xbits = 0;
        if (n >= base)
        {
            xbits = extra[n - base];
        }
        f = tree[n].fc.freq;
        state.ts.opt_len += (ulg)f *(bits + xbits);
        if (stree)
        {
            state.ts.static_len += (ulg)f *(stree[n].dl.len + xbits);
        }
    }
    if (overflow == 0)
    {
        return ;
    }
    Trace("\nbit length overflow\n");
    /* This happens for example on obj2 and pic of the Calgary corpus */
    /* Find the first bit length which could increase: */
    do
    {
        bits = max_length - 1;
        while (state.ts.bl_count[bits] == 0)bits--;
        state.ts.bl_count[bits]--; /* move one leaf down the tree */
        state.ts.bl_count[bits + 1] += (ush)2; /* move one overflow item as its brother */
        state.ts.bl_count[max_length]--;
        /* The brother of the overflow item also moves one step up,
         * but this does not affect bl_count[max_length]
         */
        overflow -= 2;
    }
    while (overflow > 0)
        ;
    /* Now recompute all bit lengths, scanning in increasing frequency.
     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
     * lengths instead of fixing only the wrong ones. This idea is taken
     * from 'ar' written by Haruhiko Okumura.)
     */
    for (bits = max_length; bits != 0; bits--)
    {
        n = state.ts.bl_count[bits];
        while (n != 0)
        {
            m = state.ts.heap[--h];
            if (m > max_code)
            {
                continue;
            }
            if (tree[m].dl.len != (ush)bits)
            {
                Trace("code %d bits %d->%d\n", m, tree[m].dl.len, bits);
                state.ts.opt_len += ((long)bits - (long)tree[m].dl.len)*(long)tree[m].fc.freq;
                tree[m].dl.len = (ush)bits;
            }
            n--;
        }
    }
}

/* ===========================================================================
 * Generate the codes for a given tree and bit counts (which need not be
 * optimal).
 * IN assertion: the array bl_count contains the bit length statistics for
 * the given tree and the field len is set for all tree elements.
 * OUT assertion: the field code is set for all tree elements of non
 *     zero code length.
 */
void gen_codes(TState &state, ct_data *tree, int max_code)
{
    ush next_code[MAX_BITS + 1]; /* next code value for each bit length */
    ush code = 0; /* running code value */
    int bits; /* bit index */
    int n; /* code index */
    /* The distribution counts are first used to generate the code values
     * without bit reversal.
     */
    for (bits = 1; bits <= MAX_BITS; bits++)
    {
        next_code[bits] = code = (ush)((code + state.ts.bl_count[bits - 1]) << 1);
    }
    /* Check that the bit counts in bl_count are consistent. The last code
     * must be all ones.
     */
    Assert(state, code + state.ts.bl_count[MAX_BITS] - 1 == (1 << ((ush)MAX_BITS)) - 1, "inconsistent bit counts");
    Trace("\ngen_codes: max_code %d ", max_code);
    for (n = 0; n <= max_code; n++)
    {
        int len = tree[n].dl.len;
        if (len == 0)
        {
            continue;
        }
        /* Now reverse the bits */
        tree[n].fc.code = (ush)bi_reverse(next_code[len]++, len);
        //Tracec(tree != state.ts.static_ltree, "\nn %3d %c l %2d c %4x (%x) ", n, (isgraph(n) ? n : ' '), len, tree[n].fc.code, next_code[len]-1);
    }
}

/* ===========================================================================
 * Construct one Huffman tree and assigns the code bit strings and lengths.
 * Update the total bit length for the current block.
 * IN assertion: the field freq is set for all tree elements.
 * OUT assertions: the fields len and code are set to the optimal bit length
 *     and corresponding code. The length opt_len is updated; static_len is
 *     also updated if stree is not null. The field max_code is set.
 */
void build_tree(TState &state, tree_desc *desc)
{
    ct_data *tree = desc->dyn_tree;
    ct_data *stree = desc->static_tree;
    int elems = desc->elems;
    int n, m; /* iterate over heap elements */
    int max_code =  - 1; /* largest code with non zero frequency */
    int node = elems; /* next internal node of the tree */
    /* Construct the initial heap, with least frequent element in
     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
     * heap[0] is not used.
     */
    state.ts.heap_len = 0, state.ts.heap_max = HEAP_SIZE;
    for (n = 0; n < elems; n++)
    {
        if (tree[n].fc.freq != 0)
        {
            state.ts.heap[++state.ts.heap_len] = max_code = n;
            state.ts.depth[n] = 0;
        }
        else
        {
            tree[n].dl.len = 0;
        }
    }
    /* The pkzip format requires that at least one distance code exists,
     * and that at least one bit should be sent even if there is only one
     * possible code. So to avoid special checks later on we force at least
     * two codes of non zero frequency.
     */
    while (state.ts.heap_len < 2)
    {
        int newcp = state.ts.heap[++state.ts.heap_len] = (max_code < 2 ? ++max_code: 0);
        tree[newcp].fc.freq = 1;
        state.ts.depth[newcp] = 0;
        state.ts.opt_len--;
        if (stree)
        {
            state.ts.static_len -= stree[newcp].dl.len;
        }
        /* new is 0 or 1 so it does not have extra bits */
    }
    desc->max_code = max_code;
    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
     * establish sub-heaps of increasing lengths:
     */
    for (n = state.ts.heap_len / 2; n >= 1; n--)
    {
        pqdownheap(state, tree, n);
    }
    /* Construct the Huffman tree by repeatedly combining the least two
     * frequent nodes.
     */
    do
    {
        pqremove(tree, n); /* n = node of least frequency */
        m = state.ts.heap[SMALLEST]; /* m = node of next least frequency */
        state.ts.heap[--state.ts.heap_max] = n; /* keep the nodes sorted by frequency */
        state.ts.heap[--state.ts.heap_max] = m;
        /* Create a new node father of n and m */
        tree[node].fc.freq = (ush)(tree[n].fc.freq + tree[m].fc.freq);
        state.ts.depth[node] = (uch)(Max(state.ts.depth[n], state.ts.depth[m]) + 1);
        tree[n].dl.dad = tree[m].dl.dad = (ush)node;
        /* and insert the new node in the heap */
        state.ts.heap[SMALLEST] = node++;
        pqdownheap(state, tree, SMALLEST);
    }
    while (state.ts.heap_len >= 2);
    state.ts.heap[--state.ts.heap_max] = state.ts.heap[SMALLEST];
    /* At this point, the fields freq and dad are set. We can now
     * generate the bit lengths.
     */
    gen_bitlen(state, (tree_desc*)desc);
    /* The field len is now set, we can generate the bit codes */
    gen_codes(state, (ct_data*)tree, max_code);
}

/* ===========================================================================
 * Scan a literal or distance tree to determine the frequencies of the codes
 * in the bit length tree. Updates opt_len to take into account the repeat
 * counts. (The contribution of the bit length codes will be added later
 * during the construction of bl_tree.)
 */
void scan_tree(TState &state, ct_data *tree, int max_code)
{
    int n; /* iterates over all tree elements */
    int prevlen =  - 1; /* last emitted length */
    int curlen; /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0; /* repeat count of the current code */
    int max_count = 7; /* max repeat count */
    int min_count = 4; /* min repeat count */
    if (nextlen == 0)
    {
        max_count = 138, min_count = 3;
    }
    tree[max_code + 1].dl.len = (ush) - 1; /* guard */
    for (n = 0; n <= max_code; n++)
    {
        curlen = nextlen;
        nextlen = tree[n + 1].dl.len;
        if (++count < max_count && curlen == nextlen)
        {
            continue;
        }
        else if (count < min_count)
        {
            state.ts.bl_tree[curlen].fc.freq = (ush)(state.ts.bl_tree[curlen].fc.freq + count);
        }
        else if (curlen != 0)
        {
            if (curlen != prevlen)
            {
                state.ts.bl_tree[curlen].fc.freq++;
            }
            state.ts.bl_tree[REP_3_6].fc.freq++;
        }
        else if (count <= 10)
        {
            state.ts.bl_tree[REPZ_3_10].fc.freq++;
        }
        else
        {
            state.ts.bl_tree[REPZ_11_138].fc.freq++;
        }
        count = 0;
        prevlen = curlen;
        if (nextlen == 0)
        {
            max_count = 138, min_count = 3;
        }
        else if (curlen == nextlen)
        {
            max_count = 6, min_count = 3;
        }
        else
        {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
 * Send a literal or distance tree in compressed form, using the codes in
 * bl_tree.
 */
void send_tree(TState &state, ct_data *tree, int max_code)
{
    int n; /* iterates over all tree elements */
    int prevlen =  - 1; /* last emitted length */
    int curlen; /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0; /* repeat count of the current code */
    int max_count = 7; /* max repeat count */
    int min_count = 4; /* min repeat count */
     /* tree[max_code+1].dl.len = -1; */ /* guard already set */
    if (nextlen == 0)
    {
        max_count = 138, min_count = 3;
    }
    for (n = 0; n <= max_code; n++)
    {
        curlen = nextlen;
        nextlen = tree[n + 1].dl.len;
        if (++count < max_count && curlen == nextlen)
        {
            continue;
        }
        else if (count < min_count)
        {
            do
            {
                send_code(state, curlen, state.ts.bl_tree);
            }
            while (--count != 0);
        }
        else if (curlen != 0)
        {
            if (curlen != prevlen)
            {
                send_code(state, curlen, state.ts.bl_tree);
                count--;
            }
            Assert(state, count >= 3 && count <= 6, " 3_6?");
            send_code(state, REP_3_6, state.ts.bl_tree);
            send_bits(state, count - 3, 2);
        }
        else if (count <= 10)
        {
            send_code(state, REPZ_3_10, state.ts.bl_tree);
            send_bits(state, count - 3, 3);
        }
        else
        {
            send_code(state, REPZ_11_138, state.ts.bl_tree);
            send_bits(state, count - 11, 7);
        }
        count = 0;
        prevlen = curlen;
        if (nextlen == 0)
        {
            max_count = 138, min_count = 3;
        }
        else if (curlen == nextlen)
        {
            max_count = 6, min_count = 3;
        }
        else
        {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
 * Construct the Huffman tree for the bit lengths and return the index in
 * bl_order of the last bit length code to send.
 */
int build_bl_tree(TState &state)
{
    int max_blindex; /* index of last bit length code of non zero freq */
    /* Determine the bit length frequencies for literal and distance trees */
    scan_tree(state, (ct_data*)state.ts.dyn_ltree, state.ts.l_desc.max_code);
    scan_tree(state, (ct_data*)state.ts.dyn_dtree, state.ts.d_desc.max_code);
    /* Build the bit length tree: */
    build_tree(state, (tree_desc*)(&state.ts.bl_desc));
    /* opt_len now includes the length of the tree representations, except
     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
     */
    /* Determine the number of bit length codes to send. The pkzip format
     * requires that at least 4 bit length codes be sent. (appnote.txt says
     * 3 but the actual value used is 4.)
     */
    for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--)
    {
        if (state.ts.bl_tree[bl_order[max_blindex]].dl.len != 0)
        {
            break;
        }
    }
    /* Update opt_len to include the bit length tree and counts */
    state.ts.opt_len += 3 *(max_blindex + 1) + 5+5+4;
    Trace("\ndyn trees: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);
    return max_blindex;
}

/* ===========================================================================
 * Send the header for a block using dynamic Huffman trees: the counts, the
 * lengths of the bit length codes, the literal tree and the distance tree.
 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
 */
void send_all_trees(TState &state, int lcodes, int dcodes, int blcodes)
{
    int rank; /* index in bl_order */
    Assert(state, lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
    Assert(state, lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, "too many codes");
    Trace("\nbl counts: ");
    send_bits(state, lcodes - 257, 5);
    /* not +255 as stated in appnote.txt 1.93a or -256 in 2.04c */
    send_bits(state, dcodes - 1, 5);
    send_bits(state, blcodes - 4, 4); /* not -3 as stated in appnote.txt */
    for (rank = 0; rank < blcodes; rank++)
    {
        Trace("\nbl code %2d ", bl_order[rank]);
        send_bits(state, state.ts.bl_tree[bl_order[rank]].dl.len, 3);
    }
    Trace("\nbl tree: sent %ld", state.bs.bits_sent);
    send_tree(state, (ct_data*)state.ts.dyn_ltree, lcodes - 1); /* send the literal tree */
    Trace("\nlit tree: sent %ld", state.bs.bits_sent);
    send_tree(state, (ct_data*)state.ts.dyn_dtree, dcodes - 1); /* send the distance tree */
    Trace("\ndist tree: sent %ld", state.bs.bits_sent);
}

/* ===========================================================================
 * Determine the best encoding for the current block: dynamic trees, static
 * trees or store, and output the encoded block to the zip file. This function
 * returns the total compressed length (in bytes) for the file so far.
 */
ulg flush_block(TState &state, char *buf, ulg stored_len, int eof)
{
    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
    int max_blindex; /* index of last bit length code of non zero freq */
    state.ts.flag_buf[state.ts.last_flags] = state.ts.flags; /* Save the flags for the last 8 items */
    /* Check if the file is ascii or binary */
    if (*state.ts.file_type == (ush)UNKNOWN)
    {
        set_file_type(state);
    }
    /* Construct the literal and distance trees */
    build_tree(state, (tree_desc*)(&state.ts.l_desc));
    Trace("\nlit data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);
    build_tree(state, (tree_desc*)(&state.ts.d_desc));
    Trace("\ndist data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len);
    /* At this point, opt_len and static_len are the total bit lengths of
     * the compressed block data, excluding the tree representations.
     */
    /* Build the bit length tree for the above two trees, and get the index
     * in bl_order of the last bit length code to send.
     */
    max_blindex = build_bl_tree(state);
    /* Determine the best encoding. Compute first the block length in bytes */
    opt_lenb = (state.ts.opt_len + 3+7) >> 3;
    static_lenb = (state.ts.static_len + 3+7) >> 3;
    state.ts.input_len += stored_len; /* for debugging only */
    Trace("\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ", opt_lenb, state.ts.opt_len, static_lenb, state.ts.static_len, stored_len, state.ts.last_lit, state.ts.last_dist);
    if (static_lenb <= opt_lenb)
    {
        opt_lenb = static_lenb;
    }
    // Originally, zip allowed the file to be transformed from a compressed
    // into a stored file in the case where compression failed, there
    // was only one block, and it was allowed to change. I've removed this
    // possibility since the code's cleaner if no changes are allowed.
    //if (stored_len <= opt_lenb && eof && state.ts.cmpr_bytelen == 0L
    //   && state.ts.cmpr_len_bits == 0L && state.seekable)
    //{   // && state.ts.file_method != NULL
    //    // Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there:
    //    Assert(state,buf!=NULL,"block vanished");
    //    copy_block(state,buf, (unsigned)stored_len, 0); // without header
    //    state.ts.cmpr_bytelen = stored_len;
    //    Assert(state,false,"unimplemented *state.ts.file_method = STORE;");
    //    //*state.ts.file_method = STORE;
    //}
    //else
    if (stored_len + 4 <= opt_lenb && buf != (char*)NULL)
    {
        /* 4: two words for the lengths */
        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
         * Otherwise we can't have processed more than WSIZE input bytes since
         * the last block flush, because compression would have been
         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
         * transform a block into a stored block.
         */
        send_bits(state, (STORED_BLOCK << 1) + eof, 3); /* send block type */
        state.ts.cmpr_bytelen += ((state.ts.cmpr_len_bits + 3+7) >> 3) + stored_len + 4;
        state.ts.cmpr_len_bits = 0L;
        copy_block(state, buf, (unsigned)stored_len, 1); /* with header */
    }
    else if (static_lenb == opt_lenb)
    {
        send_bits(state, (STATIC_TREES << 1) + eof, 3);
        compress_block(state, (ct_data*)state.ts.static_ltree, (ct_data*)state.ts.static_dtree);
        state.ts.cmpr_len_bits += 3+state.ts.static_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    else
    {
        send_bits(state, (DYN_TREES << 1) + eof, 3);
        send_all_trees(state, state.ts.l_desc.max_code + 1, state.ts.d_desc.max_code + 1, max_blindex + 1);
        compress_block(state, (ct_data*)state.ts.dyn_ltree, (ct_data*)state.ts.dyn_dtree);
        state.ts.cmpr_len_bits += 3+state.ts.opt_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    Assert(state, ((state.ts.cmpr_bytelen << 3) + state.ts.cmpr_len_bits) == state.bs.bits_sent, "bad compressed size");
    init_block(state);
    if (eof)
    {
        // Assert(state,input_len == isize, "bad input size");
        bi_windup(state);
        state.ts.cmpr_len_bits += 7; /* align on byte boundary */
    }
    Trace("\n");
    return state.ts.cmpr_bytelen + (state.ts.cmpr_len_bits >> 3);
}

/* ===========================================================================
 * Save the match info and tally the frequency counts. Return true if
 * the current block must be flushed.
 */
int ct_tally(TState &state, int dist, int lc)
{
    state.ts.l_buf[state.ts.last_lit++] = (uch)lc;
    if (dist == 0)
    {
        /* lc is the unmatched char */
        state.ts.dyn_ltree[lc].fc.freq++;
    }
    else
    {
        /* Here, lc is the match length - MIN_MATCH */
        dist--; /* dist = match distance - 1 */
        Assert(state, (ush)dist < (ush)MAX_DIST && (ush)lc <= (ush)(MAX_MATCH - MIN_MATCH) && (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
        state.ts.dyn_ltree[state.ts.length_code[lc] + LITERALS + 1].fc.freq++;
        state.ts.dyn_dtree[d_code(dist)].fc.freq++;
        state.ts.d_buf[state.ts.last_dist++] = (ush)dist;
        state.ts.flags |= state.ts.flag_bit;
    }
    state.ts.flag_bit <<= 1;
    /* Output the flags if they fill a byte: */
    if ((state.ts.last_lit &7) == 0)
    {
        state.ts.flag_buf[state.ts.last_flags++] = state.ts.flags;
        state.ts.flags = 0, state.ts.flag_bit = 1;
    }
    /* Try to guess if it is profitable to stop the current block here */
    if (state.level > 2 && (state.ts.last_lit &0xfff) == 0)
    {
        /* Compute an upper bound for the compressed length */
        ulg out_length = (ulg)state.ts.last_lit *8L;
        ulg in_length = (ulg)state.ds.strstart - state.ds.block_start;
        int dcode;
        for (dcode = 0; dcode < D_CODES; dcode++)
        {
            out_length += (ulg)state.ts.dyn_dtree[dcode].fc.freq *(5L + extra_dbits[dcode]);
        }
        out_length >>= 3;
        Trace("\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ", state.ts.last_lit, state.ts.last_dist, in_length, out_length, 100L - out_length * 100L / in_length);
        if (state.ts.last_dist < state.ts.last_lit / 2 && out_length < in_length / 2)
        {
            return 1;
        }
    }
    return (state.ts.last_lit == LIT_BUFSIZE - 1 || state.ts.last_dist == DIST_BUFSIZE);
    /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
     * on 16 bit machines and because stored blocks are restricted to
     * 64K-1 bytes.
     */
}

/* ===========================================================================
 * Send the block data compressed using the given Huffman trees
 */
void compress_block(TState &state, ct_data *ltree, ct_data *dtree)
{
    unsigned dist; /* distance of matched string */
    int lc; /* match length or unmatched char (if dist == 0) */
    unsigned lx = 0; /* running index in l_buf */
    unsigned dx = 0; /* running index in d_buf */
    unsigned fx = 0; /* running index in flag_buf */
    uch flag = 0; /* current flags */
    unsigned code; /* the code to send */
    int extra; /* number of extra bits to send */
    if (state.ts.last_lit != 0)
    do
    {
        if ((lx &7) == 0)
        {
            flag = state.ts.flag_buf[fx++];
        }
        lc = state.ts.l_buf[lx++];
        if ((flag &1) == 0)
        {
            send_code(state, lc, ltree); /* send a literal byte */
        }
        else
        {
            /* Here, lc is the match length - MIN_MATCH */
            code = state.ts.length_code[lc];
            send_code(state, code + LITERALS + 1, ltree); /* send the length code */
            extra = extra_lbits[code];
            if (extra != 0)
            {
                lc -= state.ts.base_length[code];
                send_bits(state, lc, extra); /* send the extra length bits */
            }
            dist = state.ts.d_buf[dx++];
            /* Here, dist is the match distance - 1 */
            code = d_code(dist);
            Assert(state, code < D_CODES, "bad d_code");
            send_code(state, code, dtree); /* send the distance code */
            extra = extra_dbits[code];
            if (extra != 0)
            {
                dist -= state.ts.base_dist[code];
                send_bits(state, dist, extra); /* send the extra distance bits */
            }
        } /* literal or match pair ? */
        flag >>= 1;
    }
    while (lx < state.ts.last_lit);
    send_code(state, END_BLOCK, ltree);
}

/* ===========================================================================
 * Set the file type to ASCII or BINARY, using a crude approximation:
 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
 * IN assertion: the fields freq of dyn_ltree are set and the total of all
 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
 */
void set_file_type(TState &state)
{
    int n = 0;
    unsigned ascii_freq = 0;
    unsigned bin_freq = 0;
    while (n < 7)
    {
        bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    }
    while (n < 128)
    {
        ascii_freq += state.ts.dyn_ltree[n++].fc.freq;
    }
    while (n < LITERALS)
    {
        bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    }
    *state.ts.file_type = (ush)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
}

/* ===========================================================================
 * Initialize the bit string routines.
 */
void bi_init(TState &state, char *tgt_buf, unsigned tgt_size, int flsh_allowed)
{
    state.bs.out_buf = tgt_buf;
    state.bs.out_size = tgt_size;
    state.bs.out_offset = 0;
    state.bs.flush_flg = flsh_allowed;
    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = 0L;
}

/* ===========================================================================
 * Send a value on a given number of bits.
 * IN assertion: length <= 16 and value fits in length bits.
 */
void send_bits(TState &state, int value, int length)
{
    Assert(state, length > 0 && length <= 15, "invalid length");
    state.bs.bits_sent += (ulg)length;
    /* If not enough room in bi_buf, use (bi_valid) bits from bi_buf and
     * (Buf_size - bi_valid) bits from value to flush the filled bi_buf,
     * then fill in the rest of (value), leaving (length - (Buf_size-bi_valid))
     * unused bits in bi_buf.
     */
    state.bs.bi_buf |= (value << state.bs.bi_valid);
    state.bs.bi_valid += length;
    if (state.bs.bi_valid > (int)Buf_size)
    {
        PUTSHORT(state, state.bs.bi_buf);
        state.bs.bi_valid -= Buf_size;
        state.bs.bi_buf = (unsigned)value >> (length - state.bs.bi_valid);
    }
}

/* ===========================================================================
 * Reverse the first len bits of a code, using straightforward code (a faster
 * method would use a table)
 * IN assertion: 1 <= len <= 15
 */
unsigned bi_reverse(unsigned code, int len)
{
    register unsigned res = 0;
    do
    {
        res |= code &1;
        code >>= 1, res <<= 1;
    }
    while (--len > 0);
    return res >> 1;
}

/* ===========================================================================
 * Write out any remaining bits in an incomplete byte.
 */
void bi_windup(TState &state)
{
    if (state.bs.bi_valid > 8)
    {
        PUTSHORT(state, state.bs.bi_buf);
    }
    else if (state.bs.bi_valid > 0)
    {
        PUTBYTE(state, state.bs.bi_buf);
    }
    if (state.bs.flush_flg)
    {
        state.flush_outbuf(state.param, state.bs.out_buf, &state.bs.out_offset);
    }
    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = (state.bs.bits_sent + 7) &~7;
}

/* ===========================================================================
 * Copy a stored block to the zip file, storing first the length and its
 * one's complement if requested.
 */
void copy_block(TState &state, char *block, unsigned len, int header)
{
    bi_windup(state); /* align on byte boundary */
    if (header)
    {
        PUTSHORT(state, (ush)len);
        PUTSHORT(state, (ush)~len);
        state.bs.bits_sent += 2 * 16;
    }
    if (state.bs.flush_flg)
    {
        state.flush_outbuf(state.param, state.bs.out_buf, &state.bs.out_offset);
        state.bs.out_offset = len;
        state.flush_outbuf(state.param, block, &state.bs.out_offset);
    }
    else if (state.bs.out_offset + len > state.bs.out_size)
    {
        Assert(state, false, "output buffer too small for in-memory compression");
    }
    else
    {
        memcpy(state.bs.out_buf + state.bs.out_offset, block, len);
        state.bs.out_offset += len;
    }
    state.bs.bits_sent += (ulg)len << 3;
}

/* ===========================================================================
 *  Prototypes for functions.
 */
void fill_window(TState &state);
ulg deflate_fast(TState &state);
int longest_match(TState &state, IPos cur_match);
/* ===========================================================================
 * Update a hash value with the given input byte
 * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
 *    input characters, so that a running hash key can be computed from the
 *    previous key instead of complete recalculation each time.
 */
#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
/* ===========================================================================
 * Insert string s in the dictionary and set match_head to the previous head
 * of the hash chain (the most recent string with same hash key). Return
 * the previous length of the hash chain.
 * IN  assertion: all calls to to INSERT_STRING are made with consecutive
 *    input characters and the first MIN_MATCH bytes of s are valid
 *    (except for the last MIN_MATCH-1 bytes of the input file).
 */
#define INSERT_STRING(s, match_head) \
(UPDATE_HASH(state.ds.ins_h, state.ds.window[(s) + (MIN_MATCH-1)]), \
state.ds.prev[(s) & WMASK] = match_head = state.ds.head[state.ds.ins_h], \
state.ds.head[state.ds.ins_h] = (s))
/* ===========================================================================
 * Initialize the "longest match" routines for a new file
 *
 * IN assertion: window_size is > 0 if the input file is already read or
 *    mmap'ed in the window[] array, 0 otherwise. In the first case,
 *    window_size is sufficient to contain the whole input file plus
 *    MIN_LOOKAHEAD bytes (to avoid referencing memory beyond the end
 *    of window[] when looking for matches towards the end).
 */
void lm_init(TState &state, int pack_level, ush *flags)
{
    register unsigned j;
    Assert(state, pack_level >= 1 && pack_level <= 8, "bad pack level");
    /* Do not slide the window if the whole input is already in memory
     * (window_size > 0)
     */
    state.ds.sliding = 0;
    if (state.ds.window_size == 0L)
    {
        state.ds.sliding = 1;
        state.ds.window_size = (ulg)2L *WSIZE;
    }
    /* Initialize the hash table (avoiding 64K overflow for 16 bit systems).
     * prev[] will be initialized on the fly.
     */
    state.ds.head[HASH_SIZE - 1] = NIL;
    memset((char*)state.ds.head, NIL, (unsigned)(HASH_SIZE - 1) *sizeof(*state.ds.head));
    /* Set the default configuration parameters:
     */
    state.ds.max_lazy_match = configuration_table[pack_level].max_lazy;
    state.ds.good_match = configuration_table[pack_level].good_length;
    state.ds.nice_match = configuration_table[pack_level].nice_length;
    state.ds.max_chain_length = configuration_table[pack_level].max_chain;
    if (pack_level <= 2)
    {
        *flags |= FAST;
    }
    else if (pack_level >= 8)
    {
        *flags |= SLOW;
    }
    /* ??? reduce max_chain_length for binary files */
    state.ds.strstart = 0;
    state.ds.block_start = 0L;
    j = WSIZE;
    j <<= 1; // Can read 64K in one step
    state.ds.lookahead = state.readfunc(state, (char*)state.ds.window, j);
    if (state.ds.lookahead == 0 || state.ds.lookahead == (unsigned)EOF)
    {
        state.ds.eofile = 1, state.ds.lookahead = 0;
        return ;
    }
    state.ds.eofile = 0;
    /* Make sure that we always have enough lookahead. This is important
     * if input comes from a device such as a tty.
     */
    if (state.ds.lookahead < MIN_LOOKAHEAD)
    {
        fill_window(state);
    }
    state.ds.ins_h = 0;
    for (j = 0; j < MIN_MATCH - 1; j++)
    {
        UPDATE_HASH(state.ds.ins_h, state.ds.window[j]);
    }
    /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
     * not important since only literal bytes will be emitted.
     */
}

/* ===========================================================================
 * Set match_start to the longest match starting at the given string and
 * return its length. Matches shorter or equal to prev_length are discarded,
 * in which case the result is equal to prev_length and match_start is
 * garbage.
 * IN assertions: cur_match is the head of the hash chain for the current
 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
 */
// For 80x86 and 680x0 and ARM, an optimized version is in match.asm or
// match.S. The code is functionally equivalent, so you can use the C version
// if desired. Which I do so desire!
int longest_match(TState &state, IPos cur_match)
{
    unsigned chain_length = state.ds.max_chain_length; /* max hash chain length */
    register uch far *scan = state.ds.window + state.ds.strstart; /* current string */
    register uch far *match; /* matched string */
    register int len; /* length of current match */
    int best_len = state.ds.prev_length; /* best match length so far */
    IPos limit = state.ds.strstart > (IPos)MAX_DIST ? state.ds.strstart - (IPos)MAX_DIST: NIL;
    /* Stop when cur_match becomes <= limit. To simplify the code,
     * we prevent matches with the string of window index 0.
     */
    // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
    // It is easy to get rid of this optimization if necessary.
    Assert(state, HASH_BITS >= 8 && MAX_MATCH == 258, "Code too clever");
    register uch far *strend = state.ds.window + state.ds.strstart + MAX_MATCH;
    register uch scan_end1 = scan[best_len - 1];
    register uch scan_end = scan[best_len];
    /* Do not waste too much time if we already have a good match: */
    if (state.ds.prev_length >= state.ds.good_match)
    {
        chain_length >>= 2;
    }
    Assert(state, state.ds.strstart <= state.ds.window_size - MIN_LOOKAHEAD, "insufficient lookahead");
    do
    {
        Assert(state, cur_match < state.ds.strstart, "no future");
        match = state.ds.window + cur_match;
        /* Skip to next match if the match length cannot increase
         * or if the match length is less than 2:
         */
        if (match[best_len] != scan_end || match[best_len - 1] != scan_end1 ||  *match !=  *scan ||  *++match != scan[1])
        {
            continue;
        }
        /* The check at best_len-1 can be removed because it will be made
         * again later. (This heuristic is not always a win.)
         * It is not necessary to compare scan[2] and match[2] since they
         * are always equal when the other bytes match, given that
         * the hash keys are equal and that HASH_BITS >= 8.
         */
        scan += 2, match++;
        /* We check for insufficient lookahead only every 8th comparison;
         * the 256th check will be made at strstart+258.
         */
        do
        {
        }
        while (*++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match &&  *++scan ==  *++match && scan < strend);

        Assert(state, scan <= state.ds.window + (unsigned)(state.ds.window_size - 1), "wild scan");
        len = MAX_MATCH - (int)(strend - scan);
        scan = strend - MAX_MATCH;
        if (len > best_len)
        {
            state.ds.match_start = cur_match;
            best_len = len;
            if (len >= state.ds.nice_match)
            {
                break;
            }
            scan_end1 = scan[best_len - 1];
            scan_end = scan[best_len];
        }
    }
    while ((cur_match = state.ds.prev[cur_match &WMASK]) > limit && --chain_length != 0)
        ;
    return best_len;
}

#define check_match(state,start, match, length)
// or alternatively...
//void check_match(TState &state,IPos start, IPos match, int length)
//{ // check that the match is indeed a match
//    if (memcmp((char*)state.ds.window + match,
//                (char*)state.ds.window + start, length) != EQUAL) {
//        fprintf(stderr,
//            " start %d, match %d, length %d\n",
//            start, match, length);
//        error("invalid match");
//    }
//    if (state.verbose > 1) {
//        fprintf(stderr,"\\[%d,%d]", start-match, length);
//        do { fprintf(stdout,"%c",state.ds.window[start++]); } while (--length != 0);
//    }
//}
/* ===========================================================================
 * Fill the window when the lookahead becomes insufficient.
 * Updates strstart and lookahead, and sets eofile if end of input file.
 *
 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
 *    At least one byte has been read, or eofile is set; file reads are
 *    performed for at least two bytes (required for the translate_eol option).
 */
void fill_window(TState &state)
{
    register unsigned n, m;
    unsigned more; /* Amount of free space at the end of the window. */
    do
    {
        more = (unsigned)(state.ds.window_size - (ulg)state.ds.lookahead - (ulg)state.ds.strstart);
        /* If the window is almost full and there is insufficient lookahead,
         * move the upper half to the lower one to make room in the upper half.
         */
        if (more == (unsigned)EOF)
        {
            /* Very unlikely, but possible on 16 bit machine if strstart == 0
             * and lookahead == 1 (input done one byte at time)
             */
            more--;
            /* For MMAP or BIG_MEM, the whole input file is already in memory so
             * we must not perform sliding. We must however call (*read_buf)() in
             * order to compute the crc, update lookahead and possibly set eofile.
             */
        }
        else if (state.ds.strstart >= WSIZE + MAX_DIST && state.ds.sliding)
        {
            /* By the IN assertion, the window is not empty so we can't confuse
             * more == 0 with more == 64K on a 16 bit machine.
             */
            memcpy((char*)state.ds.window, (char*)state.ds.window + WSIZE, (unsigned)WSIZE);
            state.ds.match_start -= WSIZE;
            state.ds.strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
            state.ds.block_start -= (long)WSIZE;
            for (n = 0; n < HASH_SIZE; n++)
            {
                m = state.ds.head[n];
                state.ds.head[n] = (Pos)(m >= WSIZE ? m - WSIZE: NIL);
            }
            for (n = 0; n < WSIZE; n++)
            {
                m = state.ds.prev[n];
                state.ds.prev[n] = (Pos)(m >= WSIZE ? m - WSIZE: NIL);
                /* If n is not on any hash chain, prev[n] is garbage but
                 * its value will never be used.
                 */
            }
            more += WSIZE;
        }
        if (state.ds.eofile)
        {
            return ;
        }
        /* If there was no sliding:
         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
         *    more == window_size - lookahead - strstart
         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
         * => more >= window_size - 2*WSIZE + 2
         * In the MMAP or BIG_MEM case (not yet supported in gzip),
         *   window_size == input_size + MIN_LOOKAHEAD  &&
         *   strstart + lookahead <= input_size => more >= MIN_LOOKAHEAD.
         * Otherwise, window_size == 2*WSIZE so more >= 2.
         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
         */
        Assert(state, more >= 2, "more < 2");
        n = state.readfunc(state, (char*)state.ds.window + state.ds.strstart + state.ds.lookahead, more);
        if (n == 0 || n == (unsigned)EOF)
        {
            state.ds.eofile = 1;
        }
        else
        {
            state.ds.lookahead += n;
        }
    }
    while (state.ds.lookahead < MIN_LOOKAHEAD && !state.ds.eofile);
}

/* ===========================================================================
 * Flush the current block, with given end-of-file flag.
 * IN assertion: strstart is set to the end of the current match.
 */
#define FLUSH_BLOCK(state,eof) \
flush_block(state,state.ds.block_start >= 0L ? (char*)&state.ds.window[(unsigned)state.ds.block_start] : \
(char*)NULL, (long)state.ds.strstart - state.ds.block_start, (eof))
/* ===========================================================================
 * Processes a new input file and return its compressed length. This
 * function does not perform lazy evaluation of matches and inserts
 * new strings in the dictionary only for unmatched strings or for short
 * matches. It is used only for the fast compression options.
 */
ulg deflate_fast(TState &state)
{
    IPos hash_head = NIL; /* head of the hash chain */
    int flush; /* set if current block must be flushed */
    unsigned match_length = 0; /* length of best match */
    state.ds.prev_length = MIN_MATCH - 1;
    while (state.ds.lookahead != 0)
    {
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (state.ds.lookahead >= MIN_MATCH)
        {
            INSERT_STRING(state.ds.strstart, hash_head);
        }
        /* Find the longest match, discarding those <= prev_length.
         * At this point we have always match_length < MIN_MATCH
         */
        if (hash_head != NIL && state.ds.strstart - hash_head <= MAX_DIST)
        {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
            /* Do not look for matches beyond the end of the input.
             * This is necessary to make deflate deterministic.
             */
            if ((unsigned)state.ds.nice_match > state.ds.lookahead)
            {
                state.ds.nice_match = (int)state.ds.lookahead;
            }
            match_length = longest_match(state, hash_head);
            /* longest_match() sets match_start */
            if (match_length > state.ds.lookahead)
            {
                match_length = state.ds.lookahead;
            }
        }
        if (match_length >= MIN_MATCH)
        {
            check_match(state, state.ds.strstart, state.ds.match_start, match_length);
            flush = ct_tally(state, state.ds.strstart - state.ds.match_start, match_length - MIN_MATCH);
            state.ds.lookahead -= match_length;
            /* Insert new strings in the hash table only if the match length
             * is not too large. This saves time but degrades compression.
             */
            if (match_length <= state.ds.max_insert_length && state.ds.lookahead >= MIN_MATCH)
            {
                match_length--; /* string at strstart already in hash table */
                do
                {
                    state.ds.strstart++;
                    INSERT_STRING(state.ds.strstart, hash_head);
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead.
                     */
                }
                while (--match_length != 0);
                state.ds.strstart++;
            }
            else
            {
                state.ds.strstart += match_length;
                match_length = 0;
                state.ds.ins_h = state.ds.window[state.ds.strstart];
                UPDATE_HASH(state.ds.ins_h, state.ds.window[state.ds.strstart + 1]);
                Assert(state, MIN_MATCH == 3, "Call UPDATE_HASH() MIN_MATCH-3 more times");
            }
        }
        else
        {
            /* No match, output a literal byte */
            flush = ct_tally(state, 0, state.ds.window[state.ds.strstart]);
            state.ds.lookahead--;
            state.ds.strstart++;
        }
        if (flush)
        {
            FLUSH_BLOCK(state, 0), state.ds.block_start = state.ds.strstart;
        }
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (state.ds.lookahead < MIN_LOOKAHEAD)
        {
            fill_window(state);
        }
    }
    return FLUSH_BLOCK(state, 1); /* eof */
}

/* ===========================================================================
 * Same as above, but achieves better compression. We use a lazy
 * evaluation for matches: a match is finally adopted only if there is
 * no better match at the next window position.
 */
ulg deflate(TState &state)
{
    IPos hash_head = NIL; /* head of hash chain */
    IPos prev_match; /* previous match */
    int flush; /* set if current block must be flushed */
    int match_available = 0; /* set if previous match exists */
    register unsigned match_length = MIN_MATCH - 1; /* length of best match */
    if (state.level <= 3)
    {
        return deflate_fast(state);
    }
    /* optimized for speed */
    /* Process the input block. */
    while (state.ds.lookahead != 0)
    {
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (state.ds.lookahead >= MIN_MATCH)
        {
            INSERT_STRING(state.ds.strstart, hash_head);
        }
        /* Find the longest match, discarding those <= prev_length.
         */
        state.ds.prev_length = match_length, prev_match = state.ds.match_start;
        match_length = MIN_MATCH - 1;
        if (hash_head != NIL && state.ds.prev_length < state.ds.max_lazy_match && state.ds.strstart - hash_head <= MAX_DIST)
        {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
            /* Do not look for matches beyond the end of the input.
             * This is necessary to make deflate deterministic.
             */
            if ((unsigned)state.ds.nice_match > state.ds.lookahead)
            {
                state.ds.nice_match = (int)state.ds.lookahead;
            }
            match_length = longest_match(state, hash_head);
            /* longest_match() sets match_start */
            if (match_length > state.ds.lookahead)
            {
                match_length = state.ds.lookahead;
            }
            /* Ignore a length 3 match if it is too distant: */
            if (match_length == MIN_MATCH && state.ds.strstart - state.ds.match_start > TOO_FAR)
            {
                /* If prev_match is also MIN_MATCH, match_start is garbage
                 * but we will ignore the current match anyway.
                 */
                match_length = MIN_MATCH - 1;
            }
        }
        /* If there was a match at the previous step and the current
         * match is not better, output the previous match:
         */
        if (state.ds.prev_length >= MIN_MATCH && match_length <= state.ds.prev_length)
        {
            unsigned max_insert = state.ds.strstart + state.ds.lookahead - MIN_MATCH;
            check_match(state, state.ds.strstart - 1, prev_match, state.ds.prev_length);
            flush = ct_tally(state, state.ds.strstart - 1-prev_match, state.ds.prev_length - MIN_MATCH);
            /* Insert in hash table all strings up to the end of the match.
             * strstart-1 and strstart are already inserted.
             */
            state.ds.lookahead -= state.ds.prev_length - 1;
            state.ds.prev_length -= 2;
            do
            {
                if (++state.ds.strstart <= max_insert)
                {
                    INSERT_STRING(state.ds.strstart, hash_head);
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead.
                     */
                }
            }
            while (--state.ds.prev_length != 0);
            state.ds.strstart++;
            match_available = 0;
            match_length = MIN_MATCH - 1;
            if (flush)
            {
                FLUSH_BLOCK(state, 0), state.ds.block_start = state.ds.strstart;
            }
        }
        else if (match_available)
        {
            /* If there was no match at the previous position, output a
             * single literal. If there was a match but the current match
             * is longer, truncate the previous match to a single literal.
             */
            if (ct_tally(state, 0, state.ds.window[state.ds.strstart - 1]))
            {
                FLUSH_BLOCK(state, 0), state.ds.block_start = state.ds.strstart;
            }
            state.ds.strstart++;
            state.ds.lookahead--;
        }
        else
        {
            /* There is no previous match to compare with, wait for
             * the next step to decide.
             */
            match_available = 1;
            state.ds.strstart++;
            state.ds.lookahead--;
        }
        //        Assert(state,strstart <= isize && lookahead <= isize, "a bit too far");
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (state.ds.lookahead < MIN_LOOKAHEAD)
        {
            fill_window(state);
        }
    }
    if (match_available)
    {
        ct_tally(state, 0, state.ds.window[state.ds.strstart - 1]);
    }
    return FLUSH_BLOCK(state, 1); /* eof */
}

int putlocal(struct zlist far *z, WRITEFUNC wfunc, void *param)
{
    // Write a local header described by *z to file *f.  Return a ZE_ error code.
    PUTLG(LOCSIG, f);
    PUTSH(z->ver, f);
    PUTSH(z->lflg, f);
    PUTSH(z->how, f);
    PUTLG(z->tim, f);
    PUTLG(z->crc, f);
    PUTLG(z->siz, f);
    PUTLG(z->len, f);
    PUTSH(z->nam, f);
    PUTSH(z->ext, f);
    size_t res = (size_t)wfunc(param, z->iname, (unsigned int)z->nam);
    if (res != z->nam)
    {
        return ZE_TEMP;
    } if (z->ext)
    {
        res = (size_t)wfunc(param, z->extra, (unsigned int)z->ext);
        if (res != z->ext)
        {
            return ZE_TEMP;
        }
    }
    return ZE_OK;
}

int putextended(struct zlist far *z, WRITEFUNC wfunc, void *param)
{
    // Write an extended local header described by *z to file *f. Returns a ZE_ code
    PUTLG(EXTLOCSIG, f);
    PUTLG(z->crc, f);
    PUTLG(z->siz, f);
    PUTLG(z->len, f);
    return ZE_OK;
} int putcentral(struct zlist far *z, WRITEFUNC wfunc, void *param)
{
    // Write a central header entry of *z to file *f. Returns a ZE_ code.
    PUTLG(CENSIG, f);
    PUTSH(z->vem, f);
    PUTSH(z->ver, f);
    PUTSH(z->flg, f);
    PUTSH(z->how, f);
    PUTLG(z->tim, f);
    PUTLG(z->crc, f);
    PUTLG(z->siz, f);
    PUTLG(z->len, f);
    PUTSH(z->nam, f);
    PUTSH(z->cext, f);
    PUTSH(z->com, f);
    PUTSH(z->dsk, f);
    PUTSH(z->att, f);
    PUTLG(z->atx, f);
    PUTLG(z->off, f);
    if ((size_t)wfunc(param, z->iname, (unsigned int)z->nam) != z->nam || (z->cext && (size_t)wfunc(param, z->cextra, (unsigned int)z->cext) != z->cext) || (z->com && (size_t)wfunc(param, z->comment, (unsigned int)z->com) != z->com))
    {
        return ZE_TEMP;
    } return ZE_OK;
}

int putend(int n, ulg s, ulg c, extent m, char *z, WRITEFUNC wfunc, void *param)
{
    // write the end of the central-directory-data to file *f.
    PUTLG(ENDSIG, f);
    PUTSH(0, f);
    PUTSH(0, f);
    PUTSH(n, f);
    PUTSH(n, f);
    PUTLG(s, f);
    PUTLG(c, f);
    PUTSH(m, f);
    // Write the comment, if any
    if (m && wfunc(param, z, (unsigned int)m) != m)
    {
        return ZE_TEMP;
    }
    return ZE_OK;
}

const ulg crc_table[256] = 
{
    0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL
};
#define CRC32(c, b) (crc_table[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8))
#define DO1(buf)  crc = CRC32(crc, *buf++)
#define DO2(buf)  DO1(buf); DO1(buf)
#define DO4(buf)  DO2(buf); DO2(buf)
#define DO8(buf)  DO4(buf); DO4(buf)
ulg crc32(ulg crc, const uch *buf, extent len)
{
    if (buf == NULL)
    {
        return 0L;
    }
    crc = crc ^ 0xffffffffL;
    while (len >= 8)
    {
        DO8(buf);
        len -= 8;
    }
    if (len)
    do
    {
        DO1(buf);
    }
    while (--len);
    return crc ^ 0xffffffffL; // (instead of ~c for 64-bit machines)
}

void update_keys(unsigned long *keys, char c)
{
    keys[0] = CRC32(keys[0], c);
    keys[1] += keys[0] &0xFF;
    keys[1] = keys[1] *134775813L + 1;
    keys[2] = CRC32(keys[2], keys[1] >> 24);
}

char decrypt_byte(unsigned long *keys)
{
    unsigned temp = ((unsigned)keys[2] &0xffff) | 2;
    return (char)(((temp *(temp ^ 1)) >> 8) &0xff);
}

char zencode(unsigned long *keys, char c)
{
    int t = decrypt_byte(keys);
    update_keys(keys, c);
    return (char)(t ^ c);
}

bool HasZipSuffix(const TCHAR *fn)
{
    const TCHAR *ext = fn + _tcslen(fn);
    while (ext > fn &&  *ext != '.')
    {
        ext--;
    }
    if (ext == fn &&  *ext != '.')
    {
        return false;
    }
    if (_tcsicmp(ext, _T(".Z")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".zip")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".zoo")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".arc")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".lzh")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".arj")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".gz")) == 0)
    {
        return true;
    }
    if (_tcsicmp(ext, _T(".tgz")) == 0)
    {
        return true;
    }
    return false;
}

lutime_t filetime2timet(const FILETIME ft)
{
    __int64 i = *(__int64*) &ft;
    return (lutime_t)((i - 116444736000000000) / 10000000LL);
}

void filetime2dosdatetime(const FILETIME ft, WORD *dosdate, WORD *dostime)
{
    // date: bits 0-4 are day of month 1-31. Bits 5-8 are month 1..12. Bits 9-15 are year-1980
    // time: bits 0-4 are seconds/2, bits 5-10 are minute 0..59. Bits 11-15 are hour 0..23
    SYSTEMTIME st;
    FileTimeToSystemTime(&ft, &st);
    *dosdate = (WORD)(((st.wYear - 1980) &0x7f) << 9);
    *dosdate |= (WORD)((st.wMonth &0xf) << 5);
    *dosdate |= (WORD)((st.wDay &0x1f));
    *dostime = (WORD)((st.wHour &0x1f) << 11);
    *dostime |= (WORD)((st.wMinute &0x3f) << 5);
    *dostime |= (WORD)((st.wSecond *2) &0x1f);
}

ZRESULT GetFileInfo(HANDLE hf, ulg *attr, long *size, iztimes *times, ulg *timestamp)
{
    // The handle must be a handle to a file
    // The date and time is returned in a long with the date most significant to allow
    // unsigned integer comparison of absolute times. The attributes have two
    // high bytes unix attr, and two low bytes a mapping of that to DOS attr.
    //struct stat s; int res=stat(fn,&s); if (res!=0) return false;
    // translate windows file attributes into zip ones.
    BY_HANDLE_FILE_INFORMATION bhi;
    BOOL res = GetFileInformationByHandle(hf, &bhi);
    if (!res)
    {
        return ZR_NOFILE;
    }
    DWORD fa = bhi.dwFileAttributes;
    ulg a = 0;
    // Zip uses the lower word for its interpretation of windows stuff
    if (fa &FILE_ATTRIBUTE_READONLY)
    {
        a |= 0x01;
    }
    if (fa &FILE_ATTRIBUTE_HIDDEN)
    {
        a |= 0x02;
    }
    if (fa &FILE_ATTRIBUTE_SYSTEM)
    {
        a |= 0x04;
    }
    if (fa &FILE_ATTRIBUTE_DIRECTORY)
    {
        a |= 0x10;
    }
    if (fa &FILE_ATTRIBUTE_ARCHIVE)
    {
        a |= 0x20;
    }
    // It uses the upper word for standard unix attr, which we manually construct
    if (fa &FILE_ATTRIBUTE_DIRECTORY)
    {
        a |= 0x40000000;
    }
    // directory
    else
    {
        a |= 0x80000000;
    }
    // normal file
    a |= 0x01000000; // readable
    if (fa &FILE_ATTRIBUTE_READONLY){}
    else
    {
        a |= 0x00800000;
    }
    // writeable
    // now just a small heuristic to check if it's an executable:
    DWORD red, hsize = GetFileSize(hf, NULL);
    if (hsize > 40)
    {
        SetFilePointer(hf, 0, NULL, FILE_BEGIN);
        unsigned short magic;
        ReadFile(hf, &magic, sizeof(magic), &red, NULL);
        SetFilePointer(hf, 36, NULL, FILE_BEGIN);
        unsigned long hpos;
        ReadFile(hf, &hpos, sizeof(hpos), &red, NULL);
        if (magic == 0x54AD && hsize > hpos + 4+20+28)
        {
            SetFilePointer(hf, hpos, NULL, FILE_BEGIN);
            unsigned long signature;
            ReadFile(hf, &signature, sizeof(signature), &red, NULL);
            if (signature == IMAGE_DOS_SIGNATURE || signature == IMAGE_OS2_SIGNATURE || signature == IMAGE_OS2_SIGNATURE_LE || signature == IMAGE_NT_SIGNATURE)
            {
                a |= 0x00400000; // executable
            }
        }
    }
    //
    if (attr != NULL)
    {
        *attr = a;
    }
    if (size != NULL)
    {
        *size = hsize;
    }
    if (times != NULL)
    {
        // lutime_t is 32bit number of seconds elapsed since 0:0:0GMT, Jan1, 1970.
        // but FILETIME is 64bit number of 100-nanosecs since Jan1, 1601
        times->atime = filetime2timet(bhi.ftLastAccessTime);
        times->mtime = filetime2timet(bhi.ftLastWriteTime);
        times->ctime = filetime2timet(bhi.ftCreationTime);
    }
    if (timestamp != NULL)
    {
        WORD dosdate, dostime;
        filetime2dosdatetime(bhi.ftLastWriteTime, &dosdate, &dostime);
        *timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    }
    return ZR_OK;
}

class TZip
{
public:
    TZip(const char *pwd): hfout(0), mustclosehfout(false), hmapout(0), zfis(0), obuf(0), hfin(0), writ(0), oerr(false), hasputcen(false), ooffset(0), encwriting(false), encbuf(0), password(0), state(0)
    {
        if (pwd != 0 &&  *pwd != 0)
        {
            password = new char[strlen(pwd) + 1];
            strcpy(password, pwd);
        }
    }
    ~TZip()
    {
        if (state != 0)
        {
            delete state;
        }
        state = 0;
        if (encbuf != 0)
        {
            delete [] encbuf;
        }
        encbuf = 0;
        if (password != 0)
        {
            delete [] password;
        }
        password = 0;
    }
    // These variables say about the file we're writing into
    // We can write to pipe, file-by-handle, file-by-name, memory-to-memmapfile
    char *password; // keep a copy of the password
    HANDLE hfout; // if valid, we'll write here (for files or pipes)
    bool mustclosehfout; // if true, we are responsible for closing hfout
    HANDLE hmapout; // otherwise, we'll write here (for memmap)
    unsigned ooffset; // for hfout, this is where the pointer was initially
    ZRESULT oerr; // did a write operation give rise to an error?
    unsigned writ; // how far have we written. This is maintained by Add, not write(), to avoid confusion over seeks
    bool ocanseek; // can we seek?
    char *obuf; // this is where we've locked mmap to view.
    unsigned int opos; // current pos in the mmap
    unsigned int mapsize; // the size of the map we created
    bool hasputcen; // have we yet placed the central directory?
    bool encwriting; // if true, then we'll encrypt stuff using 'keys' before we write it to disk
    unsigned long keys[3]; // keys are initialised inside Add()
    char *encbuf; // if encrypting, then this is a temporary workspace for encrypting the data
    unsigned int encbufsize; // (to be used and resized inside write(), and deleted in the destructor)
    //
    TZipFileInfo *zfis; // each file gets added onto this list, for writing the table at the end
    TState *state; // we use just one state object per zip, because it's big (500k)
    ZRESULT Create(void *z, unsigned int len, DWORD flags);
    static unsigned sflush(void *param, const char *buf, unsigned *size);
    static unsigned swrite(void *param, const char *buf, unsigned size);
    unsigned int write(const char *buf, unsigned int size);
    bool oseek(unsigned int pos);
    ZRESULT GetMemory(void **pbuf, unsigned long *plen);
    ZRESULT Close();
    // some variables to do with the file currently being read:
    // I haven't done it object-orientedly here, just put them all
    // together, since OO didn't seem to make the design any clearer.
    ulg attr;
    iztimes times;
    ulg timestamp; // all open_* methods set these
    bool iseekable;
    long isize, ired; // size is not set until close() on pips
    ulg crc; // crc is not set until close(). iwrit is cumulative
    HANDLE hfin;
    bool selfclosehf; // for input files and pipes
    const char *bufin;
    unsigned int lenin, posin; // for memory
    // and a variable for what we've done with the input: (i.e. compressed it!)
    ulg csize; // compressed size, set by the compression routines
    // and this is used by some of the compression routines
    char buf[16384];
    ZRESULT open_file(const TCHAR *fn);
    ZRESULT open_handle(HANDLE hf, unsigned int len);
    ZRESULT open_mem(void *src, unsigned int len);
    ZRESULT open_dir();
    static unsigned sread(TState &s, char *buf, unsigned size);
    unsigned read(char *buf, unsigned size);
    ZRESULT iclose();
    ZRESULT ideflate(TZipFileInfo *zfi);
    ZRESULT istore();
    ZRESULT Add(const TCHAR *odstzn, void *src, unsigned int len, DWORD flags);
    ZRESULT AddCentral();
};
ZRESULT TZip::Create(void *z, unsigned int len, DWORD flags)
{
    if (hfout != 0 || hmapout != 0 || obuf != 0 || writ != 0 || oerr != ZR_OK || hasputcen)
    {
        return ZR_NOTINITED;
    }
    //
    if (flags == ZIP_HANDLE)
    {
        HANDLE hf = (HANDLE)z;
        hfout = hf;
        mustclosehfout = false;
#ifdef DuplicateHandle
        BOOL res = DuplicateHandle(GetCurrentProcess(), hf, GetCurrentProcess(), &hfout, 0, FALSE, DUPLICATE_SAME_ACCESS);
        if (res)
        {
            mustclosehandle = true;
        }
#endif 
        // now we have hfout. Either we duplicated the handle and we close it ourselves
        // (while the caller closes h themselves), or we couldn't duplicate it.
        DWORD res = SetFilePointer(hfout, 0, 0, FILE_CURRENT);
        ocanseek = (res != 0xFFFFFFFF);
        if (ocanseek)
        {
            ooffset = res;
        }
        else
        {
            ooffset = 0;
        }
        return ZR_OK;
    }
    else if (flags == ZIP_FILENAME)
    {
        const TCHAR *fn = (const TCHAR*)z;
        hfout = CreateFile(fn, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        if (hfout == INVALID_HANDLE_VALUE)
        {
            hfout = 0;
            return ZR_NOFILE;
        }
        ocanseek = true;
        ooffset = 0;
        mustclosehfout = true;
        return ZR_OK;
    }
    else if (flags == ZIP_MEMORY)
    {
        unsigned int size = len;
        if (size == 0)
        {
            return ZR_MEMSIZE;
        }
        if (z != 0)
        {
            obuf = (char*)z;
        }
        else
        {
            hmapout = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, size, NULL);
            if (hmapout == NULL)
            {
                return ZR_NOALLOC;
            }
            obuf = (char*)MapViewOfFile(hmapout, FILE_MAP_ALL_ACCESS, 0, 0, size);
            if (obuf == 0)
            {
                CloseHandle(hmapout);
                hmapout = 0;
                return ZR_NOALLOC;
            }
        }
        ocanseek = true;
        opos = 0;
        mapsize = size;
        return ZR_OK;
    }
    else
    {
        return ZR_ARGS;
    }
}

unsigned TZip::sflush(void *param, const char *buf, unsigned *size)
{
    // static
    if (*size == 0)
    {
        return 0;
    }
    TZip *zip = (TZip*)param;
    unsigned int writ = zip->write(buf,  *size);
    if (writ != 0)
    {
        *size = 0;
    }
    return writ;
}

unsigned TZip::swrite(void *param, const char *buf, unsigned size)
{
    // static
    if (size == 0)
    {
        return 0;
    }
    TZip *zip = (TZip*)param;
    return zip->write(buf, size);
}

unsigned int TZip::write(const char *buf, unsigned int size)
{
    const char *srcbuf = buf;
    if (encwriting)
    {
        if (encbuf != 0 && encbufsize < size)
        {
            delete [] encbuf;
            encbuf = 0;
        }
        if (encbuf == 0)
        {
            encbuf = new char[size *2];
            encbufsize = size;
        }
        memcpy(encbuf, buf, size);
        for (unsigned int i = 0; i < size; i++)
        {
            encbuf[i] = zencode(keys, encbuf[i]);
        }
        srcbuf = encbuf;
    }
    if (obuf != 0)
    {
        if (opos + size >= mapsize)
        {
            oerr = ZR_MEMSIZE;
            return 0;
        }
        memcpy(obuf + opos, srcbuf, size);
        opos += size;
        return size;
    }
    else if (hfout != 0)
    {
        DWORD writ;
        WriteFile(hfout, srcbuf, size, &writ, NULL);
        return writ;
    }
    oerr = ZR_NOTINITED;
    return 0;
}

bool TZip::oseek(unsigned int pos)
{
    if (!ocanseek)
    {
        oerr = ZR_SEEK;
        return false;
    }
    if (obuf != 0)
    {
        if (pos >= mapsize)
        {
            oerr = ZR_MEMSIZE;
            return false;
        }
        opos = pos;
        return true;
    }
    else if (hfout != 0)
    {
        SetFilePointer(hfout, pos + ooffset, NULL, FILE_BEGIN);
        return true;
    }
    oerr = ZR_NOTINITED;
    return 0;
}

ZRESULT TZip::GetMemory(void **pbuf, unsigned long *plen)
{
    // When the user calls GetMemory, they're presumably at the end
    // of all their adding. In any case, we have to add the central
    // directory now, otherwise the memory we tell them won't be complete.
    if (!hasputcen)
    {
        AddCentral();
    }
    hasputcen = true;
    if (pbuf != NULL)
    {
        *pbuf = (void*)obuf;
    }
    if (plen != NULL)
    {
        *plen = writ;
    }
    if (obuf == NULL)
    {
        return ZR_NOTMMAP;
    }
    return ZR_OK;
}

ZRESULT TZip::Close()
{
    // if the directory hadn't already been added through a call to GetMemory,
    // then we do it now
    ZRESULT res = ZR_OK;
    if (!hasputcen)
    {
        res = AddCentral();
    }
    hasputcen = true;
    if (obuf != 0 && hmapout != 0)
    {
        UnmapViewOfFile(obuf);
    }
    obuf = 0;
    if (hmapout != 0)
    {
        CloseHandle(hmapout);
    }
    hmapout = 0;
    if (hfout != 0 && mustclosehfout)
    {
        CloseHandle(hfout);
    }
    hfout = 0;
    mustclosehfout = false;
    return res;
}

ZRESULT TZip::open_file(const TCHAR *fn)
{
    hfin = 0;
    bufin = 0;
    selfclosehf = false;
    crc = CRCVAL_INITIAL;
    isize = 0;
    csize = 0;
    ired = 0;
    if (fn == 0)
    {
        return ZR_ARGS;
    }
    HANDLE hf = CreateFile(fn, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
    if (hf == INVALID_HANDLE_VALUE)
    {
        return ZR_NOFILE;
    }
    ZRESULT res = open_handle(hf, 0);
    if (res != ZR_OK)
    {
        CloseHandle(hf);
        return res;
    }
    selfclosehf = true;
    return ZR_OK;
}

ZRESULT TZip::open_handle(HANDLE hf, unsigned int len)
{
    hfin = 0;
    bufin = 0;
    selfclosehf = false;
    crc = CRCVAL_INITIAL;
    isize = 0;
    csize = 0;
    ired = 0;
    if (hf == 0 || hf == INVALID_HANDLE_VALUE)
    {
        return ZR_ARGS;
    }
    DWORD res = SetFilePointer(hfout, 0, 0, FILE_CURRENT);
    if (res != 0xFFFFFFFF)
    {
        ZRESULT res = GetFileInfo(hf, &attr, &isize, &times, &timestamp);
        if (res != ZR_OK)
        {
            return res;
        }
        SetFilePointer(hf, 0, NULL, FILE_BEGIN); // because GetFileInfo will have screwed it up
        iseekable = true;
        hfin = hf;
        return ZR_OK;
    }
    else
    {
        attr = 0x80000000; // just a normal file
        isize =  - 1; // can't know size until at the end
        if (len != 0)
        {
            isize = len;
        }
        // unless we were told explicitly!
        iseekable = false;
        SYSTEMTIME st;
        GetLocalTime(&st);
        FILETIME ft;
        SystemTimeToFileTime(&st, &ft);
        WORD dosdate, dostime;
        filetime2dosdatetime(ft, &dosdate, &dostime);
        times.atime = filetime2timet(ft);
        times.mtime = times.atime;
        times.ctime = times.atime;
        timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
        hfin = hf;
        return ZR_OK;
    }
}

ZRESULT TZip::open_mem(void *src, unsigned int len)
{
    hfin = 0;
    bufin = (const char*)src;
    selfclosehf = false;
    crc = CRCVAL_INITIAL;
    ired = 0;
    csize = 0;
    ired = 0;
    lenin = len;
    posin = 0;
    if (src == 0 || len == 0)
    {
        return ZR_ARGS;
    }
    attr = 0x80000000; // just a normal file
    isize = len;
    iseekable = true;
    SYSTEMTIME st;
    GetLocalTime(&st);
    FILETIME ft;
    SystemTimeToFileTime(&st, &ft);
    WORD dosdate, dostime;
    filetime2dosdatetime(ft, &dosdate, &dostime);
    times.atime = filetime2timet(ft);
    times.mtime = times.atime;
    times.ctime = times.atime;
    timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    return ZR_OK;
}

ZRESULT TZip::open_dir()
{
    hfin = 0;
    bufin = 0;
    selfclosehf = false;
    crc = CRCVAL_INITIAL;
    isize = 0;
    csize = 0;
    ired = 0;
    attr = 0x41C00010; // a readable writable directory, and again directory
    isize = 0;
    iseekable = false;
    SYSTEMTIME st;
    GetLocalTime(&st);
    FILETIME ft;
    SystemTimeToFileTime(&st, &ft);
    WORD dosdate, dostime;
    filetime2dosdatetime(ft, &dosdate, &dostime);
    times.atime = filetime2timet(ft);
    times.mtime = times.atime;
    times.ctime = times.atime;
    timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    return ZR_OK;
}

unsigned TZip::sread(TState &s, char *buf, unsigned size)
{
    // static
    TZip *zip = (TZip*)s.param;
    return zip->read(buf, size);
}

unsigned TZip::read(char *buf, unsigned size)
{
    if (bufin != 0)
    {
        if (posin >= lenin)
        {
            return 0;
        }
        // end of input
        ulg red = lenin - posin;
        if (red > size)
        {
            red = size;
        }
        memcpy(buf, bufin + posin, red);
        posin += red;
        ired += red;
        crc = crc32(crc, (uch*)buf, red);
        return red;
    }
    else if (hfin != 0)
    {
        DWORD red;
        BOOL ok = ReadFile(hfin, buf, size, &red, NULL);
        if (!ok)
        {
            return 0;
        }
        ired += red;
        crc = crc32(crc, (uch*)buf, red);
        return red;
    }
    else
    {
        oerr = ZR_NOTINITED;
        return 0;
    }
}

ZRESULT TZip::iclose()
{
    if (selfclosehf && hfin != 0)
    {
        CloseHandle(hfin);
    }
    hfin = 0;
    bool mismatch = (isize !=  - 1 && isize != ired);
    isize = ired; // and crc has been being updated anyway
    if (mismatch)
    {
        return ZR_MISSIZE;
    }
    else
    {
        return ZR_OK;
    }
}

ZRESULT TZip::ideflate(TZipFileInfo *zfi)
{
    if (state == 0)
    {
        state = new TState();
    }
    // It's a very big object! 500k! We allocate it on the heap, because PocketPC's
    // stack breaks if we try to put it all on the stack. It will be deleted lazily
    state->err = 0;
    state->readfunc = sread;
    state->flush_outbuf = sflush;
    state->param = this;
    state->level = 8;
    state->seekable = iseekable;
    state->err = NULL;
    // the following line will make ct_init realise it has to perform the init
    state->ts.static_dtree[0].dl.len = 0;
    // Thanks to Alvin77 for this crucial fix:
    state->ds.window_size = 0;
    //  I think that covers everything that needs to be initted.
    //
    bi_init(*state, buf, sizeof(buf), TRUE); // it used to be just 1024-size, not 16384 as here
    ct_init(*state, &zfi->att);
    lm_init(*state, state->level, &zfi->flg);
    ulg sz = deflate(*state);
    csize = sz;
    ZRESULT r = ZR_OK;
    if (state->err != NULL)
    {
        r = ZR_FLATE;
    }
    return r;
}

ZRESULT TZip::istore()
{
    ulg size = 0;
    for (;;)
    {
        unsigned int cin = read(buf, 16384);
        if (cin <= 0 || cin == (unsigned int)EOF)
        {
            break;
        }
        unsigned int cout = write(buf, cin);
        if (cout != cin)
        {
            return ZR_MISSIZE;
        }
        size += cin;
    }
    csize = size;
    return ZR_OK;
}

bool has_seeded = false;
ZRESULT TZip::Add(const TCHAR *odstzn, void *src, unsigned int len, DWORD flags)
{
    if (oerr)
    {
        return ZR_FAILED;
    }
    if (hasputcen)
    {
        return ZR_ENDED;
    }
    // if we use password encryption, then every isize and csize is 12 bytes bigger
    int passex = 0;
    if (password != 0 && flags != ZIP_FOLDER)
    {
        passex = 12;
    }
    // zip has its own notion of what its names should look like: i.e. dir/file.stuff
    TCHAR dstzn[MAX_PATH];
    _tcscpy(dstzn, odstzn);
    if (*dstzn == 0)
    {
        return ZR_ARGS;
    }
    TCHAR *d = dstzn;
    while (*d != 0)
    {
        if (*d == '\\')
        {
            *d = '/';
        }
        d++;
    }
    bool isdir = (flags == ZIP_FOLDER);
    bool needs_trailing_slash = (isdir && dstzn[_tcslen(dstzn) - 1] != '/');
    int method = DEFLATE;
    if (isdir || HasZipSuffix(dstzn))
    {
        method = STORE;
    }
    // now open whatever was our input source:
    ZRESULT openres;
    if (flags == ZIP_FILENAME)
    {
        openres = open_file((const TCHAR*)src);
    }
    else if (flags == ZIP_HANDLE)
    {
        openres = open_handle((HANDLE)src, len);
    }
    else if (flags == ZIP_MEMORY)
    {
        openres = open_mem(src, len);
    }
    else if (flags == ZIP_FOLDER)
    {
        openres = open_dir();
    }
    else
    {
        return ZR_ARGS;
    }
    if (openres != ZR_OK)
    {
        return openres;
    }
    // A zip "entry" consists of a local header (which includes the file name),
    // then the compressed data, and possibly an extended local header.
    // Initialize the local header
    TZipFileInfo zfi;
    zfi.nxt = NULL;
    strcpy(zfi.name, "");
#ifdef UNICODE
    WideCharToMultiByte(CP_UTF8, 0, dstzn,  - 1, zfi.iname, MAX_PATH, 0, 0);
#else 
    strcpy(zfi.iname, dstzn);
#endif 
    zfi.nam = strlen(zfi.iname);
    if (needs_trailing_slash)
    {
        strcat(zfi.iname, "/");
        zfi.nam++;
    }
    strcpy(zfi.zname, "");
    zfi.extra = NULL;
    zfi.ext = 0; // extra header to go after this compressed data, and its length
    zfi.cextra = NULL;
    zfi.cext = 0; // extra header to go in the central end-of-zip directory, and its length
    zfi.comment = NULL;
    zfi.com = 0; // comment, and its length
    zfi.mark = 1;
    zfi.dosflag = 0;
    zfi.att = (ush)BINARY;
    zfi.vem = (ush)0xB17; // 0xB00 is win32 os-code. 0x17 is 23 in decimal: zip 2.3
    zfi.ver = (ush)20; // Needs PKUNZIP 2.0 to unzip it
    zfi.tim = timestamp;
    // Even though we write the header now, it will have to be rewritten, since we don't know compressed size or crc.
    zfi.crc = 0; // to be updated later
    zfi.flg = 8; // 8 means 'there is an extra header'. Assume for the moment that we need it.
    if (password != 0 && !isdir)
    {
        zfi.flg = 9;
    }
    // and 1 means 'password-encrypted'
    zfi.lflg = zfi.flg; // to be updated later
    zfi.how = (ush)method; // to be updated later
    zfi.siz = (ulg)(method == STORE && isize >= 0 ? isize + passex: 0); // to be updated later
    zfi.len = (ulg)(isize); // to be updated later
    zfi.dsk = 0;
    zfi.atx = attr;
    zfi.off = writ + ooffset; // offset within file of the start of this local record
    // stuff the 'times' structure into zfi.extra
    // nb. apparently there's a problem with PocketPC CE(zip)->CE(unzip) fails. And removing the following block fixes it up.
    char xloc[EB_L_UT_SIZE];
    zfi.extra = xloc;
    zfi.ext = EB_L_UT_SIZE;
    char xcen[EB_C_UT_SIZE];
    zfi.cextra = xcen;
    zfi.cext = EB_C_UT_SIZE;
    xloc[0] = 'U';
    xloc[1] = 'T';
    xloc[2] = EB_UT_LEN(3); // length of data part of e.f.
    xloc[3] = 0;
    xloc[4] = EB_UT_FL_MTIME | EB_UT_FL_ATIME | EB_UT_FL_CTIME;
    xloc[5] = (char)(times.mtime);
    xloc[6] = (char)(times.mtime >> 8);
    xloc[7] = (char)(times.mtime >> 16);
    xloc[8] = (char)(times.mtime >> 24);
    xloc[9] = (char)(times.atime);
    xloc[10] = (char)(times.atime >> 8);
    xloc[11] = (char)(times.atime >> 16);
    xloc[12] = (char)(times.atime >> 24);
    xloc[13] = (char)(times.ctime);
    xloc[14] = (char)(times.ctime >> 8);
    xloc[15] = (char)(times.ctime >> 16);
    xloc[16] = (char)(times.ctime >> 24);
    memcpy(zfi.cextra, zfi.extra, EB_C_UT_SIZE);
    zfi.cextra[EB_LEN] = EB_UT_LEN(1);
    // (1) Start by writing the local header:
    int r = putlocal(&zfi, swrite, this);
    if (r != ZE_OK)
    {
        iclose();
        return ZR_WRITE;
    }
    writ += 4+LOCHEAD + (unsigned int)zfi.nam + (unsigned int)zfi.ext;
    if (oerr != ZR_OK)
    {
        iclose();
        return oerr;
    }
    // (1.5) if necessary, write the encryption header
    keys[0] = 305419896L;
    keys[1] = 591751049L;
    keys[2] = 878082192L;
    for (const char *cp = password; cp != 0 &&  *cp != 0; cp++)
    {
        update_keys(keys,  *cp);
    }
    // generate some random bytes
    if (!has_seeded)
    {
        srand(GetTickCount() ^ (unsigned long)GetDesktopWindow());
    }
    char encbuf[12];
    for (int i = 0; i < 12; i++)
    {
        encbuf[i] = (char)((rand() >> 7) &0xff);
    }
    encbuf[11] = (char)((zfi.tim >> 8) &0xff);
    for (int ei = 0; ei < 12; ei++)
    {
        encbuf[ei] = zencode(keys, encbuf[ei]);
    }
    if (password != 0 && !isdir)
    {
        swrite(this, encbuf, 12);
        writ += 12;
    }
    //(2) Write deflated/stored file to zip file
    ZRESULT writeres = ZR_OK;
    encwriting = (password != 0 && !isdir); // an object member variable to say whether we write to disk encrypted
    if (!isdir && method == DEFLATE)
    {
        writeres = ideflate(&zfi);
    }
    else if (!isdir && method == STORE)
    {
        writeres = istore();
    }
    else if (isdir)
    {
        csize = 0;
    }
    encwriting = false;
    iclose();
    writ += csize;
    if (oerr != ZR_OK)
    {
        return oerr;
    }
    if (writeres != ZR_OK)
    {
        return ZR_WRITE;
    }
    // (3) Either rewrite the local header with correct information...
    bool first_header_has_size_right = (zfi.siz == csize + passex);
    zfi.crc = crc;
    zfi.siz = csize + passex;
    zfi.len = isize;
    if (ocanseek && (password == 0 || isdir))
    {
        zfi.how = (ush)method;
        if ((zfi.flg &1) == 0)
        {
            zfi.flg &= ~8;
        }
        // clear the extended local header flag
        zfi.lflg = zfi.flg;
        // rewrite the local header:
        if (!oseek(zfi.off - ooffset))
        {
            return ZR_SEEK;
        }
        if ((r = putlocal(&zfi, swrite, this)) != ZE_OK)
        {
            return ZR_WRITE;
        }
        if (!oseek(writ))
        {
            return ZR_SEEK;
        }
    }
    else
    {
        // (4) ... or put an updated header at the end
        if (zfi.how != (ush)method)
        {
            return ZR_NOCHANGE;
        }
        if (method == STORE && !first_header_has_size_right)
        {
            return ZR_NOCHANGE;
        }
        if ((r = putextended(&zfi, swrite, this)) != ZE_OK)
        {
            return ZR_WRITE;
        }
        writ += 16L;
        zfi.flg = zfi.lflg; // if flg modified by inflate, for the central index
    }
    if (oerr != ZR_OK)
    {
        return oerr;
    }
    // Keep a copy of the zipfileinfo, for our end-of-zip directory
    char *cextra = new char[zfi.cext];
    memcpy(cextra, zfi.cextra, zfi.cext);
    zfi.cextra = cextra;
    TZipFileInfo *pzfi = new TZipFileInfo;
    memcpy(pzfi, &zfi, sizeof(zfi));
    if (zfis == NULL)
    {
        zfis = pzfi;
    }
    else
    {
        TZipFileInfo *z = zfis;
        while (z->nxt != NULL)
        {
            z = z->nxt;
        }
        z->nxt = pzfi;
    }
    return ZR_OK;
}

ZRESULT TZip::AddCentral()
{
    // write central directory
    int numentries = 0;
    ulg pos_at_start_of_central = writ;
    //ulg tot_unc_size=0, tot_compressed_size=0;
    bool okay = true;
    for (TZipFileInfo *zfi = zfis; zfi != NULL;)
    {
        if (okay)
        {
            int res = putcentral(zfi, swrite, this);
            if (res != ZE_OK)
            {
                okay = false;
            }
        }
        writ += 4+CENHEAD + (unsigned int)zfi->nam + (unsigned int)zfi->cext + (unsigned int)zfi->com;
        //tot_unc_size += zfi->len;
        //tot_compressed_size += zfi->siz;
        numentries++;
        //
        TZipFileInfo *zfinext = zfi->nxt;
        if (zfi->cextra != 0)
        {
            delete [] zfi->cextra;
        }
        delete zfi;
        zfi = zfinext;
    }
    ulg center_size = writ - pos_at_start_of_central;
    if (okay)
    {
        int res = putend(numentries, center_size, pos_at_start_of_central + ooffset, 0, NULL, swrite, this);
        if (res != ZE_OK)
        {
            okay = false;
        }
        writ += 4+ENDHEAD + 0;
    }
    if (!okay)
    {
        return ZR_WRITE;
    }
    return ZR_OK;
}

ZRESULT lasterrorZ = ZR_OK;
unsigned int FormatZipMessageZ(ZRESULT code, char *buf, unsigned int len)
{
    if (code == ZR_RECENT)
    {
        code = lasterrorZ;
    }
    const char *msg = "unknown zip result code";
    switch (code)
    {
        case ZR_OK:
            msg = "Success";
            break;
        case ZR_NODUPH:
            msg = "Culdn't duplicate handle";
            break;
        case ZR_NOFILE:
            msg = "Couldn't create/open file";
            break;
        case ZR_NOALLOC:
            msg = "Failed to allocate memory";
            break;
        case ZR_WRITE:
            msg = "Error writing to file";
            break;
        case ZR_NOTFOUND:
            msg = "File not found in the zipfile";
            break;
        case ZR_MORE:
            msg = "Still more data to unzip";
            break;
        case ZR_CORRUPT:
            msg = "Zipfile is corrupt or not a zipfile";
            break;
        case ZR_READ:
            msg = "Error reading file";
            break;
        case ZR_ARGS:
            msg = "Caller: faulty arguments";
            break;
        case ZR_PARTIALUNZ:
            msg = "Caller: the file had already been partially unzipped";
            break;
        case ZR_NOTMMAP:
            msg = "Caller: can only get memory of a memory zipfile";
            break;
        case ZR_MEMSIZE:
            msg = "Caller: not enough space allocated for memory zipfile";
            break;
        case ZR_FAILED:
            msg = "Caller: there was a previous error";
            break;
        case ZR_ENDED:
            msg = "Caller: additions to the zip have already been ended";
            break;
        case ZR_ZMODE:
            msg = "Caller: mixing creation and opening of zip";
            break;
        case ZR_NOTINITED:
            msg = "Zip-bug: internal initialisation not completed";
            break;
        case ZR_SEEK:
            msg = "Zip-bug: trying to seek the unseekable";
            break;
        case ZR_MISSIZE:
            msg = "Zip-bug: the anticipated size turned out wrong";
            break;
        case ZR_NOCHANGE:
            msg = "Zip-bug: tried to change mind, but not allowed";
            break;
        case ZR_FLATE:
            msg = "Zip-bug: an internal error during flation";
            break;
    }
    unsigned int mlen = (unsigned int)strlen(msg);
    if (buf == 0 || len == 0)
    {
        return mlen;
    }
    unsigned int n = mlen;
    if (n + 1 > len)
    {
        n = len - 1;
    }
    strncpy(buf, msg, n);
    buf[n] = 0;
    return mlen;
}

typedef struct
{
    DWORD flag;
    TZip *zip;
} TZipHandleData;
HZIP CreateZipInternal(void *z, unsigned int len, DWORD flags, const char *password)
{
    TZip *zip = new TZip(password);
    lasterrorZ = zip->Create(z, len, flags);
    if (lasterrorZ != ZR_OK)
    {
        delete zip;
        return 0;
    }
    TZipHandleData *han = new TZipHandleData;
    han->flag = 2;
    han->zip = zip;
    return (HZIP)han;
}

HZIP CreateZipHandle(HANDLE h, const char *password)
{
    return CreateZipInternal(h, 0, ZIP_HANDLE, password);
}

HZIP CreateZip(const TCHAR *fn, const char *password)
{
    return CreateZipInternal((void*)fn, 0, ZIP_FILENAME, password);
}

HZIP CreateZip(void *z, unsigned int len, const char *password)
{
    return CreateZipInternal(z, len, ZIP_MEMORY, password);
}

ZRESULT ZipAddInternal(HZIP hz, const TCHAR *dstzn, void *src, unsigned int len, DWORD flags)
{
    if (hz == 0)
    {
        lasterrorZ = ZR_ARGS;
        return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if (han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE;
        return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->Add(dstzn, src, len, flags);
    return lasterrorZ;
}

ZRESULT ZipAdd(HZIP hz, const TCHAR *dstzn, const TCHAR *fn)
{
    return ZipAddInternal(hz, dstzn, (void*)fn, 0, ZIP_FILENAME);
}

ZRESULT ZipAdd(HZIP hz, const TCHAR *dstzn, void *src, unsigned int len)
{
    return ZipAddInternal(hz, dstzn, src, len, ZIP_MEMORY);
}

ZRESULT ZipAddHandle(HZIP hz, const TCHAR *dstzn, HANDLE h)
{
    return ZipAddInternal(hz, dstzn, h, 0, ZIP_HANDLE);
}

ZRESULT ZipAddHandle(HZIP hz, const TCHAR *dstzn, HANDLE h, unsigned int len)
{
    return ZipAddInternal(hz, dstzn, h, len, ZIP_HANDLE);
}

ZRESULT ZipAddFolder(HZIP hz, const TCHAR *dstzn)
{
    return ZipAddInternal(hz, dstzn, 0, 0, ZIP_FOLDER);
}

ZRESULT ZipGetMemory(HZIP hz, void **buf, unsigned long *len)
{
    if (hz == 0)
    {
        if (buf != 0)
        {
            *buf = 0;
        }
        if (len != 0)
        {
            *len = 0;
        }
        lasterrorZ = ZR_ARGS;
        return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if (han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE;
        return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->GetMemory(buf, len);
    return lasterrorZ;
}

ZRESULT CloseZipZ(HZIP hz)
{
    if (hz == 0)
    {
        lasterrorZ = ZR_ARGS;
        return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if (han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE;
        return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->Close();
    delete zip;
    delete han;
    return lasterrorZ;
}

bool IsZipHandleZ(HZIP hz)
{
    if (hz == 0)
    {
        return false;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    return (han->flag == 2);
}
